Private WithEvents mctlTextBox As TextBox
Private mUCsParent As UControls

Public Property Set Parent(mUCsNewValue As UControls)
    Set mUCsParent = mUCsNewValue
End Property

Public Property Set Control(ctlNewValue As Control)
    Set mctlTextBox = ctlNewValue
    mctlTextBox.OnChange = "[Event Procedure]"
End Property

Private Sub mctlTextBox_Change()
    mUCsParent.RaiseEventDirty
End Sub

Private mcolUCs As Collection
Public Event Dirty()

Public Sub AddUControl(ctlControl As Control)
    Dim UC As New UControl
    Set UC.Parent = Me
    Set UC.Control = ctlControl
    mcolUCs.Add UC, ctlControl.Name 
End Sub

Public Sub RaiseEventDirty()
    RaiseEvent Dirty
End Sub

Private WithEvents UCs As UControls

Private Sub Form_Load()
    Set UCs = New UControls
    
    With UCs
        .AddUControl Me!tbo1
        .AddUControl Me!tbo2
        .AddUControl Me!tbo3
        .AddUControl Me!tbo4
        .AddUControl Me!tbo5
    End With
End Sub

Private Sub UCs_Dirty()
    MsgBox "OK!  We've got it!"
End Sub