This place contains Windows native Visual Stidio 2008/2005 projects provided by Human. Here is his comment:
This is the result of my effort to update the project files (VC8 are untested duplicates of VC9 with changed headers, please tell me if they work). It includes the whole build_windows stuff, the rest is only an update for bugfixed C-Files and test-batches. Therefore you need the latest OC and VBISAM tarballs.
If you want to compile with BDB instead of VBISAM you have to rename open-cobol-1.1\build_windows\config_bdb.h to open-cobol-1.1\build_windows\config.h (just overwrite the old one, there is a copy open-cobol-1.1\build_windows\config_vbisam.h) and add libdb44.lib to linker (vbisam.lib and gmp.lib are done via #pragma).
I Included every fix I find working (yours about "-Wc," and "-Wl," crash the syntax tests, a copy with it can be found in open-cobol-1.1\cobc\cobc_notpassingsytaxtest.c). My fix about deleting the .obj when compiled without "--save-temps" is still in, maybe you can figure out how to take care that only the generated .obj are deleted.