XPLM_API int XPLMAppendMenuItem(
XPLMMenuID inMenu,
const char * inItemName,
void * inItemRef,
int inForceEnglish);
This routine appends a new menu item to the bottom of a menu and returns its index. Pass in the menu to add the item to, the items name, and a void * ref for this item. If you pass in inForceEnglish, this menu item will be drawn using the english character set no matter what language x-plane is running in. Otherwise the menu item will be drawn localized. (An example of why you'd want to do this is for a proper name.) See XPLMUtilities for determining the current langauge.