Code to reference variable named workbook?

I need to help several "non-Excel" people update workbooks that they use on a regular basis. I want to create code that lives in a workbook called "Fix Year Macro.xls". I plan to send all of the users this workbook/macro, so that they can run it on their individual workbooks. Obviously, all of their workbooks will have different names.

Part of the update includes copying data from the "Fix Year Macro.xls" workbook into the users' variably named workbooks. What code is necessary to add in order for the macro to reference the variably named workbooks? Kind of hard to explain...hope I'm being clear. Thanks!

I would post my code, but I don't have much so far...this is kind of my starting point.

Andrea