Ann,
It really doesn't sound all that special, the trick is just in getting the right balance of flavors, but I'll give it a shot. BTW - this dressing is believed to be of Southern origin. My Mom got the recipe from a Major's wife she babysat for in Biloxi during WW II.
Blue cheese "to taste" (I generally use somewhere in the 1/3 pound range or more, and use the cheap stuff, i.e. Stella or comparable supermarket brand. The "good" stuff is too powerful for this American concoction.)
1 to 1 1/4 cups Sour Cream
App. 1/4+ cup Mayonnaise
1/2 tsp. lemon juice
1 + 1/2 tsp. worcestershire
Crumble cheese (I use a dinner fork).
Put half of cheese, mayo, juice, worcestershire and as much sour cream as will safely fit in blender. Work it until mixed and smooth. Pour into a bowl and mix in reserved cheese chunks (whoops! and any remaining sour cream). Allow to rest for several hours or overnight before serving (or testing for personal taste!)
This will be very thick and works well as a dip for veggies (and Fritos when I was a kid). For salad dressing you may want to mix in a spoonful or two of milk.