You can build reporting extensions in the .NET lang of your choice.

Check out my article

http://www.code-magazine.com/Article.aspx?quickid=0701061

>I use WinForms Microsoft ReportViewer in local mode.
>
>I want to use C# syntax in report expressions instead on VB syntax.
>
>How to use C# instead of VB.NET syntax ?
>
>I'm thinking about the following approaches:
>
>1. Create pre-processor which converts expressions in RDL file from C# to
>VB. NET
>
>2. Replace all expressions with a method which takes C# expression as string
>parameter, evaluates it returns result.
>
>
>Any idea how to implement this ?
>
>Where to find any samples of C# expression evaluator or C# to VB .NET expression converter ?