How 2 connect midi keyb 2 mpc ny using nuendo synth?HELP

dear teachers i got a question:i have a regular m audio keystation 61 midi keyboard ,ive seen that in boon doc videos(this was just 4 u 2 to understand) he playing bass,synth and he record them live on the mpc.
My question is:i ve connected by usb my keyboard to my pc using nuendo and his virtual instrument but i can't record what i'm playing on the mpc because when i connect the midi to the midi in of the mpc i will play again the sound of the mpc!
I don't know if u understand but i hope u will help me!!!

One way of doing what you want is by connecting everything like that:

-midi keyboard's MIDI OUT (USB port) to pc MIDI IN (USB port)
-MIDI OUT from the pc to the MIDI IN of your mpc
-in Nuendo set the MIDI SOFT THROUGH to ON, so that Nuendo will resend the MIDI DATA from midi keyboard to the mpc

That way you can play the vst instruments in Nuendo and record notes on midi tracks in your mpc. Don't forget to switch the DRUM to MIDI in the main screen of your mpc.

But...
If your midi keyboard has a USB port and MIDI OUT as well, just connect the USB port to pc and MIDI OUT to MIDI IN of your mpc. Easier than the above tip, depends on what exactly you want to do with your midi keyboard. You'll figure it out.

Thx so much i ve tried with the second advise but still not work,i mean work but still playing the sound from the pads of the mpc but when i disconnect the midi from the keyboard this wil play again the synth.
about the first advise i will try but the only problem is that i cannot find the setting ur talking about(i'm new on nuendo so..)and probably cause is in italian.
Could u please help me on that either?Thx

I don't know about Nuendo, but in Cubase the MIDI SOFT THROUGH setting can be found under Preferences / MIDI Tab / MIDI Through Active. These 2 programs are pretty much similar, so try that out.