MIDI thru vs filter settings..

Ok..
I can't get in the studio till the weekend.. But have a question..

I want to know if I filtering something on input will prevent it from going thru to the output....
Similarly can I accept something on an input and prevent it going thru to the output..
Here is the scenario exactly (to help make sense)

I have a Novation SL sending messages to the MPC (specifically CC 7 on channels 1-16 ), so that I can use this as an external mixing interface.

I would also like to send a set of CC messages from an old UC-17 to a sequential six trak.. unfortunately it uses CC 7 for something...

So I want the MPC to only respond to CC7 from the the novation and NOT send it out to the six trak -----
AND
I want the MPC to send CC7 from the UC-17 to the six trak - but not respond to these messages..

If this is already possible. that's great.
if it's not I will send a feature request..

However - if that's all no good, I guess I have to invest in a MIDI merge box.

ok .. I think I just use the pad mixer function (OS 128xl) and non-channel.. (they are exclusive to each other --- so this is how it will have to be)
If I want to mix the track I will use the internal mixer.

That way I can avoid needing to send MIDI CC 7 from the novation.. and the MPC will ignore cc7 from the uc-17.. ..
No MIDI merge device needed.