I don't know what you mean by a quick launch evar.

I'm guessing you're using the theme called austerity?
If so, are you modifying iconic "quicklaunch" shortcuts?

(Where are you trying to issue the command?)

If by "quicklaunch evar" you mean an evar in $PersonalDir$evars.rc, you can't expect to define any of those with arguments because when used in themes, the evars are assumed to be quoted (to preserve paths containing spaces) and so will not be separated as the program path and any arguments. I guess it's an issue of constraints on the use of strings in litestep.

In order to get them working the way you want, you have to make the adjustment like in my previous example:
Note the evar there isn't quoted. I guess in this way, you preserve the separation of program path and arguments. I'm not sure if this would work everywhere though.