EPG Grabber Module - Update channel numbers (subchannel too)

Kick4U 2

I would like TVHeadend to include subchannels when updating channel numbers from xml files after grabber finishes.

Using 'Channel numbers (heuristic):' works when a whole integer channel number is used in the XMLTV (i.e. 4 ABC HD):
<channel id="ABC HD">
<display-name lang="en">4 ABC HD</display-name>

</channel>

How can I create the XMLTV to have TVHeadend automatically update subchannel numbers as well (i.e. 4.1 ABC Weather HD)?

Tried this, but doesn't work:
<channel id="ABC Weather HD">
<display-name lang="en">4.1 ABC Weather HD</display-name>

</channel>

Thanks

Kick4U 2

Found this feature request #4615.

http://tvheadend.org/issues/4615

Would someone help me on how to implement this?