Using multiple themes at the same time ?

[Calin VATAVU - 6A <cvatavu linux1 aut utt ro>]

Is that possible?
I mean... I want to change a theme for a widget to Marble3D and for
another widget to another  theme dinamically (trough a function, not
gtkrc)----- that's because you can't change background pixmap for a button
for example when you use Marble3D theme! I think that's a shorthand for
gtk...

thanks in advance
minitek