[AccessD] Accessing AfterUpdate Event from another procedure

Hmmmm...
I always seem to get stuck when attempting to access and run code in an afterupdate event when trying to call and execute the event
from another procedure in another module than the Form module the afterupdate event code resides in....

So what are the clear cuts on this.... please

See the code snippet below

Regards
Borge

/Code snippet:

    If FIsLoaded("frmSystem") Then
            If FIsLoaded("frmControl") Then
                Dim strSecName As String
                Dim boolModuleNamePresent  As Boolean

                strSecName = Forms("frmSystem")("SecName")
                boolModuleNamePresent = DLookup("Screen1", "tblSystem", "SecName = '" & strSecName & "'")

                If boolModuleNamePresent Then

                    Dim frm As Form
                    Dim ctrl As ComboBox
                    Set frm = Forms!frmControl
                    Set ctrl = frm!cboNav

                    ctrl.Value = "Clients"

                   'just for testing - tests ok!
                    Dim vValue0
                    Dim vValue1
                    Dim vValue2
                    Dim vValue3
                    Dim vValue4

                    vValue0 = ctrl
                    vValue1 = ctrl.Column(1)
                    vValue2 = ctrl.Column(2)
                    vValue3 = ctrl.Column(3)
                    vValue4 = ctrl.Column(4)
                   'end just for testing

                   'HERE: how do I call the AfterUpdate event of cboNav in the open form called frmControl ??

                    ' cboNav_AfterUpdate to execute here

                    Set frm = Nothing
                    Set ctrl = Nothing


                Else
                        MyMsgBox "You do not have access to the Clients Module" & vbCrLf & "Please see the System Administrator
about this!", vbInformation
                End If
            Else
                MyMsgBox "This Form requires frmControl to be loaded!", vbCritical
            End If
    Else
        MyMsgBox "This Form requires frmSystem to be loaded!", vbCritical
    End If