Match data to first row of duplicate only

Hi everyone,

I'm using index match to bring data into a worksheet. both worksheets in same workbook

tab SOURCE EmpID, Data1, Data2, Data3 etc
tab Match EmpID, 1stChoice, 2ndChoice
The match cell EMPID contains a unique employee ID number. The majority of employees have a single row of data which holds EmpID and 1stChoice but some have a single duplicate row EmpID and 2ndChoice.
I would like to be able to match Data1, Data2 etc to the first row for each EmpID but not for the duplicate row.
This is the formula I'm using
=INDEX(Data1,MATCH(SOURCE!$D3,EmpID,0))
Excel 2003

Thank you
Diddy