Private Declare Function SendMessage Lib "user32" Alias _
  "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, _
  ByVal wParam As Long, ByVal lParam As String) As Long
 
Private Const LB_FINDSTRINGEXACT = &H1A2

Dim Index As Long
 
Index = SendMessage(List1.hWnd, FINDSTRINGEXACT, -1, Text1.Text)
If Index >= 0 Then MsgBox "Gefunden: ListIndex = " & CStr(Index)