change leftmargin crystal report

Hello,

I've got a Crystal report exported to PDF.

VB Code:

Dim strStream As New System.IO.BinaryReader(rptRapport.ExportToStream(CrystalDecisions.[Shared].ExportFormatType.PortableDocFormat))

Now i want to change the leftmargin of this report.

Is that possible? And how??

Plz help

Greetz
Pietje