Go to the NNScript dropdown menu.
Go to the Tools slide out menu
Go to the Games slide out menu
Click Setup...
A new window should pop up
To the left side you'll see a Key Binding or something similar. Press it.
In there, under the key combination of your choice, type in
/run C:\Program Files\Outpost 2\Outpost 2.exe, or where ever you keep your copy of outpost.
Now hit Okay, and test it out
Mine is Shift + F3. So now, all you have to do is hit those keys.
Everyone happy? (thumbsup)
EDIT: Warning: Netfix doesn't like to work properly over mIRC when you use this. I am working on figuring out WHY/ How to get it to work right.
EDIT: I believe this is due to the way mIRC opens the game itself, and not using the Netfix items. It reverts back to the old way, but the Hamachi way still works. It's still a neat way to setup for playing OP2 singleplayer if you wanted to.