Arguments in rhinoscriptsyntax.Command

I would highly advise against going down this path (i.e. scripting macros), and instead start out with the rhinoscriptsyntax Python module or jump directly to the RhinoCommon API. For your case have a look at these methods:

https://developer.rhino3d.com/api/RhinoScriptSyntax/#mesh-MeshMeshIntersection

https://developer.rhino3d.com/5/api/RhinoCommonWin/html/M_Rhino_Geometry_Intersect_Intersection_MeshMeshAccurate.htm

https://developer.rhino3d.com/5/api/RhinoCommonWin/html/M_Rhino_Geometry_Intersect_Intersection_MeshMeshFast.htm

But before doing any of that, make sure to go through the GHPython basics here (else you’re gonna have a bad tiiime):