Integration of Ansi-C code in R under Windows

Hello at all!

I have problems with the integration of Ansi-C code into R. Using R 
Version1.8.0 under Windows 98SE I am trying to include some  code but 
neither what is written in the "Writing R Extensions"-Manual nor the 
information in the "FAQ for R under Windows" works. Maybe I have 
overlooked something, but I am not able to do what I have to.

Is someone here who could describe step by step what I have to do. I 
think the version for stupid people may be the best one.

Greatings
Harald Spohr