This message is sent whenever the Font Dialog is preparing to add a font family name, font style type, or point size entry to the combination box fields that contain these parameters.

param1
     PSZ     pFontname   /*  Pointer to the text string that is being added to the combination box. */

param2
     USHORT  usFieldId   /*  Field identifier. */
     USHORT  usFontType  /*  Font information. */