"COMSPEC path"

d:\path\tcc.exe [d:\path] [[/]@d:\path\inifile] [//directive=value...] ...
The help says the optional first argument in a start-up command line ("d:\path" above) "sets the comspec path".

What does that mean? Does it actually do anything? It doesn't seem to. Can it be eliminated?

I ask because I spent quite a while figuring out why I didn't get an automatic CWD change when I did
start %comspec v:\