Right click on the tab of the sheet that you want this functionality
added to and select View Code. Paste in the code below.
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "$A$1" Then
Columns(1).Find(What:=Target.Text & "*", After:=Range("A3"), _
LookIn:=xlFormulas, LookAt:=xlWhole, _
SearchOrder:=xlByRows, SearchDirection:=xlNext, _
MatchCase:=False, SearchFormat:=False).Activate
End If
End Sub

Confused at Work wrote:
I have a customer list in column 1 from a4 to a500. I want to be able to in
a1 type some letters and the customer corresponding to the letters i am
typing in comes up. Exactly like a search engine for excel. Any help on
this?