If there's a UI, you can feed that directly into Dwarf Fortress through DFHack, no reason to have the hash in the middle.
Well then that's good news, it'd still need to read through and identify/understand raws though with some degree of detail so that a misclick doesn't extinct your entire dwarven race or spawn a dwarf x200 taller than the norm (like i say, if it was somewhat flexible with the options on offer to also be able to edit a entry before you spawn it, for pink beards that carry over generations to scientifically show and prove genealogical processes at work if the game will allow it)
EDIT - I wouldn't push my luck on those claims, i know how firmly set the raws are in DF from raw editing, though in most terms you wouldn't be editing raws but forcing a creature into being, seeing if there was any difference would be a interesting experiment.
I recall seeing a screen for the differing race mods of masterworks, a bestiary perhaps in the same UI vein (with less fat UI bars) would best exhibit these assets being able to sort through species, gender etc etc.
Carefully getting back on topic, the theory for the capturing is set and in place, because obviously the plugin we've been talking about doesnt necessarily exist outside the land of the theoretical, using your ID splicing on a net cage to be took back and then have the creature spawned (to be herded into a cage via also dfhack) its all set.