How do you register dll's through an application object?

I am using ZenWorks to copy dll's from a network drive to the user's local
drive, and then need to register the dll's. I tried creating a batch file
with the appropriate regsrv32 commands, but it doesn't work if the user is
not an administrator.

I then found the distribution scripts, and put a command such as:
%winsysdir%system32Regsvr32.exe "c:program filesMyAppMyDll.dll"
in the 'Run after Distribution'

In the script engine, I put:

And in the extension for the script file, I put:

I've used a force run, distribute always, with version number increments.
I've also added for the user to be prompted (for my testing purposes), so
I know it's running. But it just won't register the dll.

I saw a similar thing under Run Options / Launch Scripts, and tried the
same thing there, but that didn't work either.

If I copy and past the regsvr32 line into a command prompt, it registers
it correctly, so I know there's nothing wrong with the command line.

How do I make this work?