[hanp]

1D - 1H
1NT - 4H

Kxx
Q10x
QJxx
Axx

Qxxx
AKJ9xx
xx
x

A low club is led, how do you play?

The declarer at my table won the ace, ruffed a club and led a diamond. RHO won the ace and played a third round of clubs. Declarer ruffed high, LHO following (it looks like LHO started with an odd number of clubs) and played another diamond.

LHO hopped up with the king and played the spade jack, which runs to your queen, RHO encouraging. Hearts split 2-2, how do you play?

[quiddity]

I can't see anything better than eliminating the diamonds and playing a spade to the king. Pretty sure I'm missing something.

[bonxie]

Other than eliminate diamonds and play for Ax of spades somewhere there is also this:-

Spoiler

IF you believe in your heart of hearts that LHO has 5 clubs then you can draw trumps ending in dummy and cash the diamond queen and follow with the last diamond. If RHO showed out on the Queen, you can run the diamond discarding a spade and endplay LHO who hopefully had:
J
xx
Kxxxx
HHxxx

otherwise eliminate diamonds and fall back on the doubleton Ace of spades which is your only other chance.

If LHO false-carded his club length from
AJ
xx
Kxxxx
HHxx

then buy the man a drink, he deserves it

[hanp]

LHO had J10.

[JLOGIC]

I figured thats what han was getting at.

This would probably make it an adv/expert hand, but if han had said lefty indicated an EVEN amount of clubs (say they played 3rd from even/low from odd) the play gets interesting.

We would need LHO to be 2236 now, in which case if we strip the diamonds fully by cashing the jack and ruffing one, LHO can pitch his ST to unblock the suit! In order to prevent that we should just ruff one to our hand without cashing the jack and then play a spade to prevent that possibility.