Option Explicit
 
Private Const hotkeyStrgC = "Strg+Z"
Private Const hotkeyF4 = "F4"
 
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
 
  If (KeyCode = vbKeyZ) And (Shift = vbCtrlMask) Then
    If InStr(1, mnuItem1.Caption, hotkeyStrgC) > 0 Then
      Call mnuItem1_Click
      KeyCode = 0
    End If
  End If
 
  If (KeyCode = vbKeyF4) And (Shift = 0) Then
    If InStr(1, mnuItem1.Caption, hotkeyF4) > 0 Then
      Call mnuItem1_Click
      KeyCode = 0
    End If
  End If
 
End Sub
 
Private Sub Form_Load()
  KeyPreview = True
  mnuItem1.Caption = "Test1" & vbTab & hotkeyStrgC
End Sub
 
Private Sub mnuItem1_Click()
  MsgBox "mnuItem1_Click"
 
  If InStr(1, mnuItem1.Caption, hotkeyF4) > 0 Then
    mnuItem1.Caption = "Test1" & vbTab & hotkeyStrgC
  Else
    mnuItem1.Caption = "Test1" & vbTab & hotkeyF4
  End If
End Sub

Viel Spass,
R@lf