Korg MicroArranger as MidiExpander for 2 different keyboards

[WalkyTalky]

(German version see below)

Hello,

I'm new to this board and relatetively new to my little Arranger Keyboard.
I bought it as a Midi-Sound Generator for my Masterkeyboard. That's working fine, but I would like to use also the builtin keyboard for other sounds. In the manual I read someting about different Soundchannels, I wonder, if it's possible, to use these channels with different keyboards at different Midi-Channels and don't know, how to switch the instruments at these different channels. In former times I used a Roland SoundCanvas and switched the Midi Channels, to switch the instruments, but with the MicroArranger, I don't know, how to manage the diffent sounds.
I hope you understand what I mean. Perhaps you can help me..
Regards from Germany

WalkyTalky

Da mein Englisch scheinbar für diesen Post nicht ausreicht, hier nochmal die deutsche Version:
Ich habe einen Korg MicroArranger und möchte ein MasterKeyboard über Midi-In anschließen. Und beide Keyboards, das interne und das externe sollen unterschiedliche Sounds verwenden. Und das am besten so, daß es einfach ist, zwischen den Sounds hin und her zu schalten.
Könnt Ihr mir sagen, was ich dazu einstellen muss?

WalkyTalky