I wish your advice...
My formula result ERROR , I thing VLOOKUP function can not meet the expected
condition (APPLY DATE<=C1<=END DATE).
Do you have any kind of solution for this case?

A B C D
1 MAIN DATA ENTER DATE: 20041215--constant
2 PART NO PRICE
3 1A ??? ==Formula=IF(AND($A1=VLOOKUP($A1;
4 1B ??? A7:C10;1;FALSE);
$C$1=VLOOKUP($A1;A7:C10;
2;FALSE);$C$1<=VLOOKUP
($A1;A7:C10;3;FALSE));
VLOOKUP($A1;A7:C10;4);
"ERROR")
5 SOURCE DATA
6 PART NO APPLY DATE END DATE PRICE (USD)
7 1A 20010101 20031201 1.5
8 1A 20031202 99991201 1.0
9 1B 20010101 20040501 5.0
10 1B 20040502 99991231 6.0

Regards,
Oso