how do I create a fontset at runtime ?

[Ionutz Borcoman <borco borco-ei eng hokudai ac jp>]

Hi,

Fontsets looks very nice and useful. However at the oresebt I can use
them only via a rc file. I would like to create a font set at runtime
from 2 font names, but I am falling to find any info about this. So
please help me.

I brief:

1. Have 2 font names;
2. I want to make from them a fontset;
3. I want to aply the fontset to an entry and some buttons;
4. All this has to be done at runtime and how often the user of my
program chooses to do so.

TIA,

Ionutz