Jamba will not do what you are asking, neither will any other addon or macro that I am aware of.
The way I do it is, I use Quest Guru for my quest log, makes it double pane, gives a quest history, a couple other features and gives the number of other players on the quest right next to it. This way all you have to do is look for any quest that does not have 4 other party members on it. (assuming you are 5 boxing and grouped up)
I know this is not what you are looking for, and I may just dig into an "Share All Quests" option some where as it is a good idea.