There currently is no "good" way to do this with the existing fixture libraries.
The H3 only allows two patch points per fixture as well, so a custom profile won't work either.
Your best bet is to program them as 3 Generic Desk Channels from the start, or make sure all your dimmer numbers line up in proper RGB sequence (Red @ 1, Green @ 2, Blue @ 3, etc...) and patch as RGB LED fixrures.
Are you starting a new show or trying to "Change Type" from an RGB LED to PARs?
The only way I can think of to make this sort-of work is: - clone ("Replicate") each RGB LED fixture twice (giving you the original and 2 copies) - then make sure all your PARs have dimmers that are at least 3 DMX channels away from one another. - then patch your first fixture (a Red PAR) @ DMX 001, and plug into dimmer 1 - your next fixture (a Green PAR) @ DMX 004, but plug into dimmer 5 - and your third (a Blue PAR) @ DMX 007, but plug into dimmer 9
You will run out of DMX "space" 3 times as quickly though, so be careful.
This is really klunky, and you would be much better off lining up the dimmers as stated above, or programming them separately as Desk Channels from the start.
[QUOTE=cormacjack;47012]why not base it on the axon or media server model. 3 x layer which can be patched at any address?
I don't think this would work as there is a fundamental difference in how that works.
The AXON/DL GFX layers are all separate "fixtures" as far as the desk is concerned. So this "model" is the same as using 3 Desk Channels.
What is essentially needed in this case is a way to split out parameters from within a fixture and patch them to different locations.....not really the best way to work as things can get ugly in your patch very quickly.