Didn't try the program, so I'm not entirely sure how it works.
But are you familiar with Temporary Keyboard Overrides (added in 2006)? They might make this routine unnecessary, if you're running 2006 or 2007. Basically, holding down SHIFT or SHIFT+some other key can change various settings. By default, holding down SHIFT toggles ORTHO mode. So, if you're in the middle of a command and suddenly need to use ORTHO for one selection, you can simply hold down SHIFT and make the selection. Similarly, if ORTHO is already on, holding down SHIFT will disable ORTHO until you release SHIFT again.
Holding down SHIFT in conjunction with other keys will trigger a running OSNAP temporarily. For example, I can hold down SHIFT+C at any time, and get the CENTER osnap. Similarly, SHIFT+E activates the END osnap, SHIFT+Z activates the PERP osnap, SHIFT+R activates the NEAR osnap, etc. This behavior is completely customizable in the CUI. (The CEN and END overrides are there by default, but I had to create the PERP and NEAR ones myself...)
The only real drawback is that Autocad sometimes gets confused, and mis-interprets a Temporary Keyboard Override as Text Entry. Then the keyboard repeat kicks in, and you can get a string of letters like "ccccccccccccc" instead of the CEN osnap. But all-in-all, it's a very handy feature.
Holding down SHIFT and right-clicking the mouse also calls up the OSNAP shortcut menu, which is handy. Starting in either 2006 or 2007, there's a "Snap to mid between 2 points" option that should have been added years ago...