[sgqwonkian]

...or, you could alter the quest that gives the Ambassador in the first place. Add to it a line of "SVAR mukamb yes" just above or below "ITEM ps_mukamb".
Then in the quest you're trying to make, set a CONDITION block with
"TYPE uvar
STR0 mukamb
STR1 yes"

So there's a couple different ways to work around it.