[pygtk] Using custom font

[Mauro Giacomini]

Hi, I have a problem with fonts.
There is a way to use a custom font in a pygtk app?
I am in this situation:
I want to use a particular font in my app and this font is present in my 
system.
I can use pango function to use the font in my app, but if someone else 
that don't has such font in his system, what can he do?
I read the pygtk documentation but I don't found a function to load a 
font from an external ttf file.
Is there such a function in pygtk?
Or there is another solution?

Thank in advance,
Mauro G.