Help - How can i add "Custom Button" on page [Create Page option available to admin only]

Hi,

I am new to Elgg and PHP, need your help for my college project.

# I want to add "Confirm your presence - Button" at bottom of page created by Admin [Create Page option available to admin only] 

# I also want to get guid of users how have confirmed and want to export the result in excel for offline refernce.

Please help !!!

 

Thanks in advance,

Harsh vardhan