Not sure what you mean by cannot access ?
The way i resolved this was as Joel had described simply view the code for the report in the report class library. Then in my example i wanted to access a report parameter named "Status" to determine which image to display. So my code looked like :
Dim mySatus as String = Report.ReportParameters.Item("Status")
If myStatus = "Draft" Then
Me.Style.BackgroundImage.ImageData = System.Drawing.Image.FromFile("C:\YourDocPath\Draft.png")
ElseIf myStatus = "Approved" Then
Me.Style.BackgroundImage.ImageData = System.Drawing.Image.FromFile("C:\YourDocPath\Approved.png")
Also think you will need a :
declaration to access the required classes.
Thats is should be good to go with that.
Hope this helps.