I have multiple monthly reports in excel (example: Jan08_ABC.xls) that
reference particular spreadsheets that also change monthly
(Jan08_ABC_cases.xls). I've created a formula that gets the values it needs,
however I'm trying to figure out how to get the formula to change every
month.

For instance, the formula for January is ='[Jan08_ABC_cases.xls]Sheet1'!$B6
I need it to change for each new month.

I created another formula in cell A1 that will automatically update monthly
with the new name of the needed/referenced file, therefore in Feb that cell
reads Feb08_ABC_cases.xls. So, my question is how do I change my initial
formula to incorporate the name change.

These don't work, but hopefully it gives you a good idea of what I'm trying
to do (A1=Feb08_ABC_cases.xls):
='[(TEXT(A1,"")]Sheet1'!$B6
='[A1]Sheet1'!$B6