Reach a subForm on a report

[lonchi]

Hy every one,
I am tryng to update a row source of a control that is on a Report.
I tried several methods, but I don't seem to get it working.

I figured that I can place a subForm on a Report and than get to its's control RowSource.

My code is like this :
[Report]![ReportName].[Form]![sfrmOnReport]![ControlNameOnsfrmOnReport].RowSource = strSQL

This does not work.
I get " Microsoft Access can't find field '|' referd to your expression.

The whole idea is to make a report depending on wat is selected on the form.

If anyone has another mathod for achierf this, pleas let me know.

Thanks