Datareport

OK, probably very very beginner but here it goes anyway.
I have a dataenvironment which is the datasource for a datareport, how do I change the command at runtime. I had something like this:

Dim ReportSQL as string
...
ReportSQL = "Select * from ... 'it changes almost every time I come to this form
...
DataEnvironment.Connection1.Execute (ReportSQL)
DataReport.Show




This doesn't seem to work...any suggestions?

Thanks

If anything in this post makes sense it was written by me, if not I don't know who wrote it