Opening / executing / utilizing non-Microsoft programs from VBA ?

Ok, here's an interesting one I've come across; I'll state the general problem first, then go into the more detailed one (btw, if the latter is not possible, help on at least the general problem would be a great help!):

General:
I'm looking for a way to open or launch a non-Microsoft application with VBA code (I'll most likely add a button in the workbook for others to do this with)

Specific #1 (easier):
Let's say I'd like to be able for a user of the workbook to click a button, and have a webpage come up. To compound this problem, there will be a pop-up window asking for a user ID and password (which is a group password, so there is no issue with setting this up to do automatically)

Specific #2 (much harder):
How about allowing the user to click a button, which launches a UNIX-based program, which brings up a box looking for a user ID and password (also a group password, so no issues there). What would be nice is if I could program VBA to launch this .exe file, fill in the User ID and Password, then CONTROL the UNIX program's drop down menus (which will allow ALT+F for the file menu, for example). What I guess I really need here is to be able to program keystrokes, since every time this is done, the keystrokes are EXACTLY the same.

Any suggesions?

Thanks.
- Thomas M.