a really simple way would be to edit the Footer options at ato->Edit POST/PAGE INFO ITEMS and add the test you want. For example at 'FOOTER: Homepage' it has
HTML Code:
%date('F jS, Y')% | %tags-linked('Tags: ', ', ', ' | ')% Category: %categories-linked(', ')% | %comments('Leave a comment', 'One comment', '% comments', 'Comments are closed')% %edit(' | ', 'Edit this post', '')%
you could change it to
HTML Code:
%date('F jS, Y')% | %tags-linked('Tags: ', ', ', ' | ')% Category: %categories-linked(', ')% | %comments('Leave a comment', 'One comment - please leave yours', '% comments - please leave yours', 'Comments are closed')% %edit(' | ', 'Edit this post', '')%
other than that, it means digging into the code to do what you want.