Possible way to counter or sidestep split-second spells (like Trickbind) in a particular situation
Yes, that would work. After activating the regeneration ability, you get priority:


  117.3c If a player has priority when they cast a spell, activate an ability, or take a special action, that player receives priority afterward.


so you can activate it again. Trickbind does not counter any (other) abilities of the permanent already on the stack.