From the midiox help function:
[quote:2d3rois2]OutputMidiMsg(nPort, nStatus, nData1, nData2)
This method sends a MIDI message out all MIDI ports that are mapping the channel. The nStatus parameter is a combination of the MIDI status and channel. Data1 and Data2 values depend on the MIDI message.
[/quote:2d3rois2]
I have searched for a clear description of this ‘combination of midi status and channel’, but never found it. I remember to have found some examples that use a format of "175+midichannel#" that work. In this specific case, the 176 value specifies CC messages sent on channel 1 of the specified port (which I have made a variable that is specified separately).