Hi, I have this problem, too.

Changing the content in Reportserver Database does not seem to be a feasible solution to me. I do not want to think of what could happen if the subscription execution fails for any reason.

If I understood it correctly, this solution will also only work if you want to set the reportname only once per execution of the subscription (and then back to origin).

If you want to set it for every entry in the data driven subscription source query you will have to change the data during the execution of the subscription, which would be only possible using a stored proc as dummy datasource which does this any time the report is executed...

@josh - There is no filename attribute which you could define in an email subscription.