Option Explicit
Sub Suchen()
Dim suche As Range
Dim zaehler As Long
For zaehler = 2 To Workbooks(1).Worksheets(1).Range("A" & Rows.Count).End(xlUp).Row
Set suche = Workbooks(1).Worksheets(2).Range("A2:A" & Workbooks(1).Worksheets(1).Range("A" & Rows.Count).End(xlUp).Row).Find(Workbooks(1).Worksheets(1).Cells(zaehler, 1))
If Not suche Is Nothing Then
Workbooks(1).Worksheets(1).Cells(zaehler, 2) = Workbooks(1).Worksheets(2).Cells(suche.Row, 2)
End If
Next zaehler
End Sub