The version I use is:
4NT asks for Key Cards (the four Aces and the King of Trumps).
The responses are:
4C* = 1 or 4
4D* = 0 or 3
4H = 2 without the Queen of Trumps
4S = 2 with the Queen of Trumps
5NT asks for Kings but not the trump King as you have already asked for it. the responses are the same as normal Blackwood.
Some players reverse the Club and Diamond* responses (0 or 3 then 1 or 4). The responses above are not the full story but lets keep it simple!