Why not use the��PATH environment variable in Windows to��do what you want? I deal with setting variables used with LibC in my blog entry at��https://fuhrmanator.github.io/2019/03/16/LibC-Pharo-experiments.html

You can get PATH by using:

�� �� path := OSEnvironment current getEnv: 'PATH'.

Then you can add your directory to it (note that I put a semicolon for path separator in Windows):

�� �� modifiedPath :=�� 'D:\DEV_FreeCAD\build\bin\;'��+ path.

Then you have to set the variable in the system:

�� �� result := OSEnvironment current setEnv: 'PATH' value: modifiedPath.

You should probably get (again) the variable PATH (as above) to make sure the path was set correctly.

Then just do:

�� �� result := LibC runCommand: 'makebox.step'.

Let us know if it works for you.

Cheers!