Key press + mouse press shortcuts

[Peter Clark <mailinglistalias@forrussia.org>]

    This is more general than just KDE, but there might be a KDE specific 
solution I don't know about, so I'll go ahead and ask. I just bought a Genius 
NetScroll+ Superior mouse today, which comes with (count 'em) 10 buttons. It 
works well with Linux--only the application switch button doesn't work. 
Doesn't even register in xev. I can live with that, though. What I would like 
to do is add a little "chording" functionality to it. Four of the buttons are 
actually keys--that is, they return keyboard presses, rather than mouse 
button presses. So I thought I could make the "play" button (keycode 162) act 
as a modifer key--probably mod_3, since that's not assigned to anything. So 
far, so good. Here's the meat of the question: is there some way so that by 
pressing "play" + left mouse button to get a keystroke? I would like "play" + 
lmb to return enter, and "play" + rmb to return delete. I checked out 
khotkeys and keyboard shortcuts in KControl, but didn't see anything that 
would let me do a combination key press + mouse press.
    Thanks,
    :Peter