Hello Everyone,
I'm looking for a function that will do the following:

Look for a reference in a column, 2010 for instance, and whenever it finds a
2010 in column "a" it returns what is in the same row in column "b" into a
single cell in a format like:
a, b, d
see the example below:

2010 a
2010 b
4030 c
2010 d