Why not re-write completely the OHRRPGCE in Qbasic?
From OHRRPGCE-Wiki
This article only applies to the DOS/QuickBasic version. It is not relevant for the current Windows and Linux versions
The OHRRPGCE was originally written in QuickBasic 4.5. It was later ported to FreeBasic and there has also been some work porting it to other languages. Qbasic is a simplified free version of QuickBasic. It is the same as QuickBasic except that it has more limited support for assembly language, and cannot produce standalone EXE files. Porting the OHRRPGCE to Qbasic would be a step backwards (from a starting point that is already pretty far back)
