Ah hah! Thanks to googling for "perl keyboard hook", I came across this! I'm surprised that I didn't think of the word "hook" for this - would have saved me some trouble. This should do the trick once I get some time to sort through it. Thanks much for the lead :)!
Comment on Re^2: Reading keyboard input without focus
Unfortunately all that code does is register a hot key. It's just a windows API call that enables a program to receive global hot keys (e.g. CTRL+ALT+Z). It won't allow your program to receive all keyboard input.
There is a good essay on how to set up a global mouse hook over at the code project