There is a snippet in vs to get the data source of of crystal report viewer.
Dim report As New ReportDocument()
Dim server as String
Dim DBName as String
report.Load("rptPatient.rpt")
server=report.DataSourceConnections(0).ServerName
DBName=report.DataSourceConnections(0).DatabaseName
Here Server give the name of server in the report (first connection). And DBName gives the name of Data Base.
Thanks.