run a .vbs in another directory?

Ok I know how to call a .vbs file that is in the same directory as my script.py by using the code os.system(.vbs script).
However, when I do the exact same thing, only I define my my .vbs script as a file in another directory, it says that it cannot find the file specified. I know that I am defining the .vbs script correctly because I try the exact same thing on, for example, a .cmd, and it works fine. So there is something going on that is preventing me from running a .vbs file when it is in a different directory than my mainscript.py. Any input?