use the sumif function.. ie if in worksheet B you have
COlA COlB
Andy 20
Andy 30
Fred 40
then in worksheet A cell(1,1) you enter the name of the person, in cell (1,2) enter the formula
Code:
=SUMIF('C:\temp\[Book2.xls]Sheet1'!$A$2:$A$4,A1,'C:\temp\[Book2.xls]Sheet1'!$B$2:$B$4)
you can change the file path.
first arguement is equivilent to COlA
second arguement is the location of the search name
third arguement is the range to be summed
hope this helps