Hi Peter,
I have not encountered any path problems with gxo2 or co2. Oxide can use either compilers, which it invokes using the full pathname in quotes.
Various ways to invoke gxo2.exe:
make an association between .o2bas scripts and gxo2.exe, then you can double-click on any o2bas script to run it.
Run from IDE: Oxide or Scite.
Drag scripts onto the gxo2 icon or a gxo2 shortcut.
Drag script onto the upper part of the Oxide window.
Use directly from the console, or a batch file.