a) I would look on the MSDN CD's first. If you can't find it there, a decent advanced book about VB would probably have the info you need. Your DLL can use MFC (statically linked is my advice), but it cannot be an extension DLL (it must be a "regular" DLL). You also cannot use CStrings as parameters or return values. b) I don't know anything about VB, so I can't answer that. c) You might look into writing an ATL COM DLL. It's supposed to be much easier to use from disparate languages (assuming you can use a COM DLL from within your fortran app - if not, forget this option). "...the staggering layers of obcenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001