How can I justify text in a multicolumn listbox cell dynamically

[andreasl]

I use a multicolumn listbox with two columns to display an event list. Then number of events is different and can exceed the number of displayed rows. I need to justify the text in the first column to right dynamically.
Is there any way?

[DOC-doc]

I would split the listbox in two different listboxes, each one with its specific format (make it static).