I want to do an `INDEX-MATCH`-like lookup between two documents, except my `MATCH's index array` doesn't stay in one column.  

In Vague-English: I want a value from a known column that matches another value that may be found in any column.

Refer to the image below. Let's call everything to the left of the bold vertical line on column H doc1, and the right side will be doc2. 

Doc2 has a column "Find This", which will be the `INDEX's array`. It is compared with "ID1" from doc1 (Note that the values in "Find This" will *not* be in the same order as column ID1, but it's easier to undertsand this way).

The "[Result]" column in doc2 will be the value from doc1's "Want This" column from the row that matches "FIND THIS" ...However, sometimes the value from "FIND THIS" is not in the "ID1" column, and is instead in "ID2","ID3", etc.  

So, I'm trying to generate Col K from Col J. This would be like pressing `Ctrl+F` and searching for a value in Col J, then taking the value from Col D in that row and copying it to Col K.

I made identical values from a column the same color in the other doc to make it easier to visualize where they are coming from.

[![Example documents](https://i.stack.imgur.com/upcCz.png)](https://i.stack.imgur.com/upcCz.png)

Note also that in column F of doc1, the same value from doc2's "Find This" can be found after some other text. 
Also note that the column headers are only there as examples, the ID columns are not actually numbered.

I would simply hard-code the correct column to search from, but I'm not in control of doc1, and I'm worried that future versions may have new "ID" columns, with other's being removed.

I'd prefer this to be a solution in the form of a formula, but VB will do.