adding my own button in sub menu of calc

Dear friends,
Able to add new button and submenu in the calc menubar bar , when cursor moves on the new menubar button the green background comes & added sub menu items are displayed but the green background does not comes when cursor moves on the sub menu button. The task is attach a functionality to sub menu button like on clicking the button a document or image gets open. how link button with a functionality of my own
thanx in advance
Pune Uni,