Please help me create a formula that finds the minimum non-zero amount in a
column (B) based on the condition that there is a date in the adjacent column
(C). Some cells in both columns will be blank (e.g. cells C2, C5 and row 6 is
blank). Example below should return result of $400 as the minimum in cell E1.

Column A Column B Column C
1 item1 $1000 11/17/08
2 item2 $800
3 item3 $600 11/24/08
4 item4 $400 11/30/08
5 item5 $200
6

Thank you in advance for you assistance!