Link Just To Log In In Footer

i dont have sidebars i just need to put a link in the footer for when theres updates, just for the admin, i have like 50 blogs i dont want to type wp-admin in them

Upload a txt file in some hosting of yours and code a script to read that file and just display what's in there and paste on all your blogs.
Then all you have to do when updating all footers is changing the txt file

i cant code.....................