Hi Randy,
I doubt that you did anything wrong...but here's what I'd recommend that you try:
- Open your ISM and go to the Components view under Organization.
- Select the component that is supposed to launch this file you're associating.
- Click on Advanced and go to File Types.
- Hopefully your file extension will appear here. If not, you may have the wrong component.
- Lastly, make sure that the "Argument" is surrounded in quotes.
I hope this helps!
Cheers,
Robin