For anyone not familiar with this, it allows you to use the mouse scroll wheel in a userform and the full code can be viewed here

I know it works in a userform, however I'm trying to use it for an ActiveX ComboBox.

I've set it to trigger as:
Private Sub ComboBox1_DropButtonClick()
HookListBoxScroll ComboBox1, ComboBox1.ComboBox
End Sub
However I'm getting a
Run-time error '438':
Object doesn't support this property or method

Does it simply not work outside a userform or is it something I've done wrong with the syntax here:

HookListBoxScroll ComboBox1, ComboBox1.ComboBox
as needs to be the format of
HookListBoxScroll(frm As Object, Ctl As MSforms.control)

I'll never take the scroll wheel for granted again!