FabFilter

I'm not sure if that is exactly possible with Pro C but something similar would be to duck only the Mid channel with the sidechain input. Now here I'm assuming that the Mid channel in your mix comprises of low frequency sounds in order to achieve a similar effect as ducking only the low freqs.
Not sure if i'm making any sense :D

Hi David,

You cannot do that in Pro-C2, Multiband compressors are the tool for that kind of process.

What you could do, though, is duplicate the Instrument track and split it into frequency areas:
On one of them put a High pass filter, and on the other a Low cut filter (using the same settings of course)
After doing that you could put the Pro-C2 on the low frequency track (the one you put high-cut on), and this should more or less do the job.

But why, though? :}

MB is definitely the way to do it.

Cheers

I accidentally wrote 'high pass filter', I meant High CUT filter

("On one of them put a High pass filter...."