Combo Allow Auto Complete

in a combo on Win pc after having enabled Auto Complete by starting to type a search the combo shows all the lines starting with the typed characters, beautiful and very useful, on the mac instead the search is only completed with the content of a line that looks like as much as possible to the typed one and it is of little use. On pc win I think the APIs complete the job, is there any trick to make everything similar to the pc win combo?
Excuse my english