Yes, that's the idea. You probably need to wrap the exe command with "" if spaces are required.
If -allow_hardware_refresh is enabled in switchres.ini, new modes will be added dynamically (no need to use VMMaker for that, Switchres uses the same mechanism as VMMaker for adding/removing modes on the fly). You may hear a plug/unplug sound from your Windows os though, due to this.
If -allow_hardware_refresh is disabled, Switchres will try to update your existing modelines, just like GM does, without adding new modes.