Retrieval of available scripts for certain fonts

[Vag]

Hello.
I'm writing an editor that is to be used in several languages.
I want the user to be able to select any of the installed fonts, and I use a combo box for this.
Because of the different languages though, I want the user to be able to select the script (Charset) for the selected font. The available scripts will be in a second combo box.
The problem is that not all fonts have the same scripts!
For example, a certain font could have Western, Greek, Cyrillyc, when another font could have Western, Greek and Chinese!

So, when the user selects a font, I have to retrieve all the available scripts for this font, I hope this is clear.
Does anyone know how I do this?
Thanks.