Changing font with capi::display-tooltip

Dear list,

Is there a way to change the font of the tooltips displayed with  
capi::display-tooltip ?
I guess this might be possible since the default font (displayed for  
instance in the example file "examples/capi/graphics/pinboard- 
help.lisp") is not the same as the LW IDE tooltips (at least on  
Macintosh) ...  but I did't find out how to do it.
Thanks for any help


Jean Bresson