It sounds much more correct to use "to", as saying "at", to me, sounds like you are "coming back" in terms of a "comeback", as though the door has insulted you, and now you're "going back at" it.
It's as though you are attacking the door in some way.
Also, I don't know what the context is, but I imagine that in the vast majority of cases you'd actually be wanting to say: I went right back to her door.
ell.stackexchange.com/users/103986/Chris Mack
I think the correct phrase is: I came right back to her door.
In my interpretation, assuming the speaker intends to imply they are walking towards the door from another location, "I came back at her door" is incorrect.
"I came right back
" describes what action was taken. "at" or "to" defines the location at which the action took place. "her door." descibes the destination.
I would say "at"
implies the speaker was already at the door when they "came back" whereas "to" implies the target of the action of "coming back" as the speaker describes.
Consider the following:
I walked right back at her door.
I would say this implies the speaker is already at the door and then walked, whereas: I walked right back to her door.
I would say this implies the speaker is walking towards the door and did not necessarily begin there.
In conversational English (which is pretty lenient to errors like this and will provide better context) I think both could be used to say more or less the same thing, but the sentence with "to" makes more sense to me.
In writing at any level above conversational I would consider "at" to be an error assuming the writer intends to describe the speaker as walking towards the door.
I would use "at" in instances when you wanted to describe the speaker not moving relative the door, or observing the door, for example:
I stood at her door.
or I gazed at her door.
ell.stackexchange.com/users/107119/Nimphious
They are both correct but have different nuances:
I rang her doorbell
but she was not home
so I went to do some shopping.
Afterwards, I came right back to her door and tried the bell again.
compared to:
I was the duty firefighter when we were called out to her house.
On arriving, I looked through the window and could see her on the floor in the hallway.
I started to use the fire axe to break down the door
then there was an explosion which sent me backwards.
I came right back at her door , attacking it with the axe.
If you are going "to" the door then you are going to the location of the door but if you are going "at" the door then you are performing an action at the door.
ell.stackexchange.com/users/46301/MT0
One related thing that I don't see covered by the other answers: while "came right back at her door" means something quite strange, this doesn't mean that "at her door" is always wrong. "
to her door" emphasizes travel/motion/action, while "at her door" talks more about the door as a location or end state.
For example, you might write, Just an hour later
, I was right back at her door. to give the impression that your actions were beyond your control: you just couldn't help but go back.
You found yourself at her door without thinking about the act of going there.
ell.stackexchange.com/users/5229/amalloy
Most often, you come to a door.
You don't come at a door.
Likewise, you come to a party.
You don't come at a party.
Well, I guess it depends on the party.
Another exception to this rule may be a bro.
You can come to a bro for help, or you can come at a bro to fight.
I guess what it boils down to is your intended action once you get to the door.
If your intentions are good, then you come to the door.
If your intentions could potentially cause conflict, especially against the door itself, then I suppose you could come at the door.
I hope that clears things up for you.
ell.stackexchange.com/users/107151/Andy C
I came back to her door.
This means that I left, then at a later time returned to the location of the door.
I came back at her door.
This (could) mean that I was playing a game, was killed, and my respawn point was next to the door.
ell.stackexchange.com/users/10015/Ross Presser
Both are grammatical.
The only difference I can fathom is that, if you're using the former, then your objective of going back is tethered with the door, and not her .
ell.stackexchange.com/users/106717/Noaman Ali
If it is spoken word as opposed to text; Coming right at the door of a female could be misinterperated as slang for directing your semen toward her vagina or buttock region at the point of sexual climax, depending on whether it was the front door (vagina) or back door (anus).
For example; "I'd like to smash her back door in" can mean
"I would like to have anal intercourse with her" .
The verbs 'to come' and 'to cum' are pronounced the same, however, 'to cum' means to ejaculate, hence the potential for confusion.
ell.stackexchange.com/users/107166/Dr Love
"At" also can mean "on the surface of", also it does not sound like one could use it in normal conversation.
Something like "my image on a door" may be a way to use it :
She had TVs everywhere.
She saw my image on the kitchen's TV and turned it off screaming.
I came right back at her door.
ell.stackexchange.com/users/98093/Alexei Levenkov
What would be correct between these two lines (please explain) :   I came right back at her door.   Or   I came right back to her door.
"I came right back AT her door" or "I came right back TO her door"?
ell.stackexchange.com
<word-usage><word-choice>
ell.stackexchange.com/questions/234419
ell.stackexchange.com/users/104902/Sigma
I think the correct phrase is:   I came right back to her door.    Both are correct but the meanings are different. The preferred expression in this context would be "I came right back to her door". 
Both are correct but the meanings are different. The preferred expression in this context would be "I came right back to her door". 