Hi, if you only need to select one of the numbers in B:B, the following
*array* formula might also work for you (assuming data in A2:B8):

=SMALL(IF(A2:A8="A",B2:B8),INT(RAND()*COUNTIF(A2:A 8,"A"))+1)

As an array formula it must be entered with the key combination
Shift+Ctrl+Enter.

HTH
Kostis Vezerides