ID number L-number Supplier
1245 L-1234 Green
3456 L-1234 Smith
1237 L-1234 Homer
3456 L-3256 McDonald
2423 L-2435 Homer
7765 L-2222 Green
2543 L-2222 Smith
8769 L-5678 MCDonald

=INDEX(A1:C9;MATCH("L-1234";B1:B9;0);MATCH("ID number";A1:C1;0))

In the following case each product has an unique ID-code. Also each prodct
has a L-number, based on the supplier. I use the INDEX/MACTH combination to
lookup information. In this case I have the L number, and want to find the
correct ID number per supplier. So I want the ID number from L-1234 IF (in
case) the supplier is Green.

How can I combine the above mentioned INDEX/MATCH with an IF-function?