Catch DLL errors in Visual Basic

I have a functional DLL created using Fortran that I use in Visual basic 6. If a runtime error occurs from a function in the DLL, then the VB program crashes and the error cannot be trapped in VB. Anyone has solution to this problem? Source code for testing is included, please see the attached file. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 3) Complete ownership and distribution copyrights to all work purchased. ## Platform Windows 2000