Combining lookup functions with data validation

Hi
I have a table like this in A1:B11:

Name Code
Fred 3511
Jack 3512
Alice 3513
Lora 3514
John 3515
Ann 3516
Fred 3517
Lora 3518
Alice 3519
Fred 3520

for example I want to Lookup all codes of Fred by drop down list in data validation.
Thanks