check if element of a control array exists

[Pinky98]

try to create the object.. if it gives you an error then an object exists in that location.
you would use "On Error Resume Next" and "On Error Goto 0".

On Error Resume Next
    Load ArrayCtl(23)
    If (Err.Number <> 0) Then
        'Clear the error
        Err.Clear
        Resume
        'Do what ever you would want if the object did not exist
        ...
        ...
    Else
        'Do what ever you would want if the object did exist
        ...
        ...
    End If
On Error Goto 0

You can also simply access the object instead of attempting to create it. The same approach can be used for both.