Simple Find Values?

You should be able to do it like this:

=IF(A1=C1&D1,TRUE,FALSE)

Where in this example;
A1 contained 4112JJPV

C1 contained 4112JJ
D1 contained PV

So C1 and D1 would be the cells in your 'other table' and A1 would be the cell you are comparing it to.

EDIT Ooops, sorry, I think perhaps I didn't quite understand the question, in which case the above will be no use to you. I don't think you can use VLOOKUP as that will only return the first instance of the first 6 characters it finds in your 'other' table. You would perhaps either need to add another column to your 'other table' that joins the 2 parts together again, and then check against that, or else use a VBA macro.