Converter for icon in ComboBox

Hi everybody,

I have in my datasource a column that let me, after some calculations, know which icon i should use for this item. I assumed the best way to do it was to use a converter<ressource,columntype>, so I have 2 questions:
_Does another way already exists to make this transformation ?
_If nonoe exists, how could i extend a combobox to let him use converters for icons too ?