Absolutely! I've got a demo up at http://www.activevfp.com/avfpdemo2/default.aspx. BTW, you only need the free .NET Framework to do this. Just run TLBIMP over the .vfp. mtdll. Here's the code:
(<% is not translating properly here):

<% @Page Language="C#" ASPCompat="true" %>
<% @Import Namespace="avfpdemo2_dotnetproxy" %>
<%
server x ;
x = new server() ;
try
   {
	Response.Write(x.main());
   }
catch(Exception ex)
   {
       	Response.Write("Caught .NET exception, source: " + ex.Source + " message: " + ex.Message);  
   }

%>

>Can a DLL written in VFP be used by Dot Net C# ?
>
>I do not even know how to develop a DLL, but I want to be able to share a validation routine wih a Dot Net program that views the same MS SQL data that my VFP 8 application is using.
>
>We tried using SQL stored procedures, but had problems with the return values.