1NT - 2D
2H - 3C
Where 3C is game-forcing showing a second suit. Continuations are:
- 3H = 3-card support, no support for clubs
- New suit = cue supporting clubs, doubleton heart
- 3NT = no support for either suit
- 4C = 3 hearts, 4+ clubs
With this agreement, I would be comfortable trying 3C to find out about heart length. I'm pretty certain I can convince partner I was just joking about clubs.