Hi
As Paul said it all depends on what the 'index' contains.
eg if it is a simple number for each month 1 through to 9999 then there is a way of doing it, not to complex.
If it contains a date ref even better eg 01-03-11/1

Either way it is all very doable and would not necessarily need a macro.

May be an idea to post an example ?

Regards
Matthew