I think that this should only be a change to RPEL, like making it programmable and the ctype could be the particle it affects. The temp affects its "attractivness" like it always has. Leaving the ctype blank would make it work for any particle.
One thing I don't get, will it have a wide range or will the "strength" only affect the amount it repels, when the particle is near. Edit: oh now i understand the range part