Question: How do I use regex to convert 

```
11111aA$xx1111xxdj$%%`

```

to 

```
aA$xx1111xxdj$%%

```

So, in other words, I want to remove (or match) the FIRST grouping of `1`'s.

Answer: 
If this is the beginning, you can use this:

```
^[1]*

```

As far as replacing, it depends on the language. In powershell, I would do this:

```
[regex]::Replace("11111aA$xx1111xxdj$%%","^[1]*","")

```

This will return:

```
aA$xx1111xxdj$%%

```
In Javascript 

```
    var str  = '11111aA$xx1111xxdj$%%';
    var patt = /^1+/g;
    str      =  str.replace(patt,"");

```