Add additional heart rate zones (i.e, more than 5)

I want to know if it is possible to add additional heart rate zones to an activity type?  For example, each standard or custom activity has a total of 5 zones, however, I would like to add two more zones to my running activity so that I have 7 total zones.  The training program I am using now has 7 total zones.

I considered just setting my Garmin zone 1 to equal my training plan zone 2, and my Garmin zone 5 to equal my training plan 6, but I would like to be able to set a bottom end and top end to training plan zones 1 and 7.  And I would think this is an easy enough feature to implement.  

If this is currently not possible, then consider this a feature request, and please direct me to a more appropriate location in the forums to place such a request.

Thanks!