Tvheadend

Hi,

My IPTV provider has the following format for channels:

#EXTM3U
#EXTINF:-1,1. БНТ 1
http://cdn.provider.com:88/sc.php?stid=1&mac=MA:CA:DD:RE:SS&key=7011b111
#EXTINF:-1,2. bTV
http://cdn.provider.com:88/sc.php?stid=2&mac=MA:CA:DD:RE:SS&key=7011b111
#EXTINF:-1,3. Nova

The key changes on every request for the m3u file and i can't keep it cached because it's only valid for 15 minutes or so.

I know that if the URL changes then the channel will be considered a new one by TVHeadend. So the question is how do i make TVHeadend ignore the key part of the url?

If the functionality does not exist I don't mind writing the code myself but would appreciate some pointers.