Locate a record on a browse using multi component key

I have a browse procedure on a file ordered by a multi component key


Record                   RECORD,PRE()
AreaNumber                          LONG      
ItemId                              LONG  

I’m trying to use locator class to be able to locate first record with a given AreaNumber and ItemId, but it only seems to work for single component keys. How can I locate a record and positon the browse cursor on the first last matching entry