I have this formula in cell B1.
=VLOOKUP(A1,[Book1]Sheet1!$A:$M,2,FALSE)

In cell A2, I have a file name/location
In cell A3, I have a worksheet name

I would like to alter this formula so that instead of [book1], it can point
to cell A2 and look for whatever file I type in there. The same with the
worksheet name Sheet1, I'd like it to point to A3 so I can type that in too.

I would do this the standard way, however due to the number of vlookups on
this spreadsheet, I need to be able to type the file name and worksheet name
into these cells, and have all the vlookups adjust accordingly. I know
find/replace does work for that, but only in a permament formula. I need
something variable.

Thanks for your help!