Oh good lord...
For folks not absolutely clear, the DS will not communicate with a Gamecube....for starters, look at the GBA-GC cable. Its made for the GBA's expansion ports, which the DS lacks!
That clue aside, it would technically be possible to create a peripheral for the Cube to allow it to communicate wirelessly with the DS....but they won't.
Thats a losing cause, so your only hope down that road would be if some enterprising HK outfit cobbled together such a device. But really, just use your SP if Cube connectivity is essential for you.
Finally, DS does not play GBC games. Its not even technically possible outside of emulation. The GBA had an actual GBC processor inside it, makiing backwards compatibility a snap, just as the DS has a GBA processor inside it. Lacking that GBC processor however, the DS will not natively playback GBC games...and now, my heartfelt condolences to your poor, poor GBC cart =(