ExcelBanter - Combine two workbooks into one

I'd like to set up a macro to combine two seperate workbooks into ONE
workbook. Here's the scenario.

We make spreadsheets for clients that make purchases from us that hold
relevant information to that specific buyer and save it named "[buyer] -
[lotnumber]". Buyer and Lotnumber are named ranges in the workbooks that
contain information. Because we're collecting a lot of information these
days (and they refuse to let me go to a database), it's become easier to do
updates to all of these workbooks by splitting them into two seperate
workbooks.

So now, the consultants will open these two books (named universal.xls as it
contains sheets that are relevant to each buyer, and CORE-[model].xls because
they pertain to a certain class of buyer). Once they have the universal
workbook open they'll open the relevant core workbook, enter all the data and
from there... they'll want to save. It would be much easier if they could
save both the universal and core workbooks in one file. I'll leave the save
location up to the consultant, I just need the code to combine both of those
workbooks.

The tricky part is this. The unviversal workbook will always be
"universal.xls", however the core workbook will vary because of the "model"
extension at the end (ie "CORE - Penington.xls, CORE - Brighton.xls", etc.)