You need to look into Panels and Lite-C / C-Script...
Code:
PANEL new_game_pan
{
pos_x = 0; pos_y = 0;
bmap = bg_bmap;
button = 5,0,new_game_bmp,new_game_bmp,new_game_on_bmp,New_Game,NULL,NULL;
button = 15,32,load_game_bmp,load_game_bmp,load_game_on_bmp,Load_Game,NULL,NULL;
button = 25,64,quit_game_bmp,quit_game_bmp,quit_game_on_bmp,Quit_Game,NULL,NULL;
layer = 1;
flags = OVERLAY | TRANSLUCENT;
}