I believe from previous discussions on this forum you have to have a Triforce with a memory card port for the adapter to plug into. IIRC the port resembles a DB9 serial port but it may have a different pin count. None of my three Triforce mobos have this.
However, you might be able to get around this and install the memory card right in the GameCube memory slot. It would not be at all convenient, especially if you're expected to remove it.
Barring that, you could maybe do a passive DIY adapter wiring pin for pin to the GC memory card slot.
From what I gathered from prior discussions, there's not much to be gained from having the memory card functionality unless you're planning to play on a GC as well.