Here is an example:

Private Sub CrystalSetDataSource()

Dim i, j As Integer
Dim Subreport As CRAXDRT.Report

'Set table properties in main report
Call CrystalSetTableProperties_QuickBooks(g_crReport)

'Set table properties in all subreports
With g_crReport
For i = 1 To .Sections.Count
For j = 1 To .Sections(i).ReportObjects.Count
If (.Sections(i).ReportObjects(j).Kind = crSubreportObject) Then
Set Subreport = .OpenSubreport(.Sections(i).ReportObjects(j).SubreportName)
Call CrystalSetTableProperties_QuickBooks(Subreport)
End If
Next j
Next i
End With

End Sub

Private Sub CrystalSetTableProperties_QuickBooks(Report As CRAXDRT.Report)

'Set QuickBooks connection properties
With Report.Database.Tables.Item(1)
.ConnectionProperties.DeleteAll
.ConnectionProperties.Add "DSN", g_vcDSN_QuickBooks
End With

End Sub

There a a few constants and variables that would need to be changed for your own use, hopefully they are evident enough.