the problem about mixed language(C#+vc.net)

Question

i passed the value get from below:

-------------
///////////////////////////
C#:
[System.Security.Permissions.PermissionSet

(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")]
        protected override void WndProc(ref Message m)
        {
            if (m.Msg == 55 && Drvloaded)
            {
                long test = dp.OnReply(Convert.ToUInt32(m.WParam.ToString()),

m.LParam.ToInt32());

            }
            base.WndProc(ref m);
        }
/////////////////////////////
vc.net
long OnReply(UInt32 wParam,long lParam);
-------------

then after the process by vc.net,i want to pass back some vale(type about

"char/long/WORD..etc) to c#

how i can work this out on "vc.net",thanks

ps:
vc.net,CLR Project