Lookup Based On Variable/Changing Sheet Name

I'm trying to figure out a way to lookup a value based on a conditional sheet name. I'm finding it difficult to explain in words what I'm trying to do, so I'm going to try and describe it in a miniature example of my spreadsheet. I apologize if this is going against forum rules, this seems like the quickest way to get my question across:

The following is the way my spreadsheet's first page is set up:

ID Apr-08 Mar-08 Feb-08
1
2
3

The column labels depend on another table, which changes monthly.
The rest of the sheets (24 of them, labled "200804", "200803", etc) look like this:

ID $ amount Date paid
1
2
3

I have another table upon which the na

I'm trying to return the "Date Paid" value for each ID for each month. Each month, however, more data arrives, and the labels change. I have several dozen spreadsheets formatted in this way, and I'm trying to avoid having to change the vlookup (or other formula) manually each month for each sheet. Is there a way to make the vlookup depend on a table?

This is essentially what my formula looks like right now for cell A2:
=VLOOKUP($A2,'200804'!$A$1:$G$10000, 3, FALSE)

If I could replace '200804' with a cell reference, that would be ideal. I haven't been able to figure out how (if possible); I tried experimenting with index sheets but that went nowhere.