[Sebastian2]

so sieht es momentan aus:

Private Sub cmb_plz_BeforeUpdate(Cancel As Integer)
OrtFinden
End Sub

und im Modul:

Sub interessenten()

End Sub

Sub OrtFinden()
Dim o_rst As Recordset

Set o_rst = CurrentDb.OpenRecordset("select * from ortsdaten")
With o_rst
.FindFirst "PLZ=" + Form_interessenten.cmb_plz.Text
If .NoMatch = False Then
Form_interessenten.tb_Ort = !Ort
End If
End With
End Sub