How do I create user-friendly drop-down lists where you can select multiple options?

You might try going a different way with it. See attached sheet. I identified a list of choices and named the range [VALID_OPTIONS] and the target cell is just named [THE_CELL].


Code needed:

Sub RoundedRectangle1_Click()
Dim c As Range
Dim s As String
If Intersect(Selection, [VALID_OPTIONS]) Is Nothing Then Exit Sub

For Each c In Intersect(Selection, [VALID_OPTIONS])
    s = s & ", " & c.Value
Next c
'Remove first comma and space, return value to sheet'
[THE_CELL].Value = Right(s, Len(s) - 2)
End Sub