We frequently have SSRS reports that compare this month vs last month. I use synonyms in the main report query in order to avoid the messiness of constructing a dynamic sql statement. The reports are based on sprocs where the first thing that happens is redefining the synonyms to point to the month end snapshots the user requests via report parameters.
That's a pretty creative solution to managing repetitive files where the date is part of the names. I have a couple of processes to implement this way. Thanks for posting it.
Sigerson
"No pressure, no diamonds." - Thomas Carlyle