assuming that the path is a text string as a reference, try
="C:/excel/"&MONTH(A8)&"_"&YEAR(A8)&"/filename.xls" where A* is the date.
Remember, this will not update the actual path, only the reference in a field.

"phxwsd" wrote:

I'm trying to setup a spreadsheet so that when someone enters a date in the
first field, it exports the month and year to another field containing a path
to data from another spreadsheet.

For example, if the path is C:/excel/09_2006/filename.xls, how can I set
this up so when you type in the date of 10/1/2006 it updates the path called
for to C:/excel/10_2006/filename.xls?

Thanks for any advice