Its ugly but we have to opem 2C,2nt forced 3C and 3D show 5D+4/5H GF.
4C show 2keycard with 4H and non minimum.
4D should be best used as general slam try but for us its asking for Q of trumps.
I would just bid 4H with responder but ive post the rest of the sequence if north is optimist.
4S is show the Qh but not the K of C, 5D is bypassing Kd/KS ask for extras wich has to be CQ here,
Edited its 6H not 6D