interp invokehidden path ?-global? hiddenCmdName ?arg ...?
Invokes the hidden command hiddenCmdName with the arguments supplied in the interpreter denoted by path. No substitutions or evaluation are applied to the arguments. If the -global flag is present, the hidden command is invoked at the global level in the target interpreter; otherwise it is invoked at the current call frame and can access local variables in that and outer call frames.