[sdiy] MIDI Switch

[Moho Disco]

I want to make a little box with
a 3-way switch on it that changes
incoming midi on channel 1 to 
channels 1, 2, or 3.  I'd like to
do it with only one MIDI in and
one MIDI out.  I don't want to
make a switcher with 3 outs.

Do you guys think this would be
hard to make?  And would I have
to program an eeprom or something
to accomplish this?

Thanks,

Lava