I don't have one that uses yogurt, but I'll give you my recipe, just in case...
I don't know if you can make my recipe to fit your way-of-eating (I watch carbs myself, but maybe it would work with the low fat version of the ingredients?), but what I use is:
- about 1 cup of mayo and 1 cup of sour cream
- 1 package of Knorr vegetable soup mix
So, that makes a bunch, but it keeps for awhile. I really, really like it, and it's what I always bring to potlucks if I'm on veggie-duty.