Excel 2007- compare columns - return values

Hello,

Excel 2007.

I have 5 columns A, B, C, D and E. Column A and B are of equal length, column C is longer. Columns D and E are still empty. So:
A: a list of names with x rows of data
B: a list of numeric values with x rows of data
C: a list of names with x+y rows
D: empty
E: empty

Further, column B shows a value that belongs to the name in column A on that row; column C is ordered randomly.
And finally: all columns are subject to frequent changes (names added/removed, numeric values change); not all names in column A are in column C or vice versa.

I would like to compare each name from column C with column A, and if there is a match, i want to return that matching name to column D. The corresponding value from column B should end up in column E.
I would also like to do the same, but this time with each name from column A compared to column C, and return the matching name in D and the value from B to E.

Obviously, i can't get it done :-( and i hope someone knows how to do this! Thank you in advance."