. . .

You don't pass data /to/ events.
Use properties (Get and Set) to pass data into the UserControl,
then "handle" the events raised /by/ the UserControl back your
"main" application.  Over-simplifying this:

Class MyUserControl
   . . .
   Public Event X_Changed()
   . . .
   Public Property X() as Integer
       Get
           Return m_iX
       End Get
       Set( Value as Integer )
           m_iX = Value
           RaiseEvent X_Changed
       End Set
   End Property
   Private m_iX as Integer = 0
End Class

Class Form1
   Friend WithEvents uc1 as MyUserControl
   . . .
   Private Sub Button1_Click( _
     byVal sender as Object _
   , ByVal e as EventArgs _
   ) Handles uc1.Button1_Click

       uc1.X = 99

   End Sub

   Private Sub uc1_X_Changed( _
     byVal sender as Object _
   , ByVal e as EventArgs _
   ) Handles uc1.X_Changed
       MsgBox "Something changed X"
   End Sub
End Class

HTH,
   Phill  W.