I have a list of parts that are in Kits (like a socket set). It is two
columns A = PARTS and B = KIT. It is sorted by Parts. one part can be in
more than one kit and that is what I need to know.

example:

PART KIT
Part_A Kit_1
Part_A Kit_2
Part_A Kit_3
Part_B Kit_2
Part_B Kit_3
Part_C Kit_1

The above array is in a named range called KIT_DATA. And I was going to use
vlookup untill I realized it would only give me the first kit. The above
data is in Sheet2. Sheet1 lists all of the Parts. The objective is to
insert a comment into the Part on sheet1 and put all the Kits that the part
is in (from sheet2 or KIT_DATA) into the comment.

Soooo....

Sheet1

Part_A would have a comment "Kit_1, Kit_2, Kit_3"
Part_B would have a comment "Kit_2, Kit_3"
Part_C would have a comment "Kit_1"

Does that make sense? Can anyone help? I could loop through the whole mess
but it's about 50,000 lines.

DG