Populate combobox from a pivot

[urobee]

Hy,
I have an excel userform with a combobox.
I want to fill the combobox with values from a pivot.

The pivot contains hundreds of columns with two rows.
The first row contains the column headers and some of the second row contains some value.
I want to fill the combobox with those column headers where the second row is not empty.

Thanks for Your help!