MIDI ROUTING : op1 as a MIDI controller and midi clock settings


I am able to set my oplab into midi clock slave mode but :
I can’t figure out how to NOT transmit midi clock output .

In other words , is possible to filter the thru messages for the midi clock ?

Or in other words , I want the op1/oplab to be slave and I don’t want the oplab to transmit a midi clock out .

Because in my entire midi patch set-up, I want to use the OP1 as a midi controller for the master clocking device .

Anybody ?

thank you for your help