I have a long equation that I will be using over and over in an excel sheet but I have not programmed in VBA before. I am very good at Java though.

my equation is this:

ROUND(-SUMIF('[FileName.xlsx]Data'!$V:$V,$A13&$B13&$C$7&LEFT($C$11,3),'[FileName.xlsx]Data'!$I:$I),-3)/1000

To explain:
ROUND(
-SUMIF(
'[FileName.xlsx]Data'!$V:$V, [long column with string of IDnumber (x), year (Y), and category(Z).... so an example of a value is XXXXYYYYZZZ]
$A13&$B13&$C$7&LEFT($C$11,3), [Column A = IDnumber(x), Column B = year(Y), column C= category(Z)]
'[FileName.xlsx]Data'!$I:$I) return the sume of the finding's values in column I
,-3) rounding to thousands

Can anyone help???