How to perform midi note -> external synth while playing pad

So there is a task i can't seem to find a workaround for.

I'm using an MPC1000 to play an external synth by assigning pads to midi notes, let's say i have a four note riff to play i can assign a row of pads to different midi notes and play the riff with the pads.

While doing this i'd like to trigger some other pads with samples assigned to them, like sound fx, but if i play those pads it will ALSO send its own midi note number and trigger sounds on the synth, the synth is mono so it always messes up whatever i'm trying to play, you can't seem to turn off midi note out for only certain pads.

I'm thinking of setting these samples sound pads to very low note#s and then using a midi filter to filter out low notes so the synth won't play them, but i'm wondering if there's a solution that doesn't require more gear ?

looks like i'll have to purchase a midi solutions event processor and filter out the lowest notes so that i can use pads with samples without triggering my synth... anyone has a workaround ? this thing is really expensive for what it does.