ok here is my first replay on this forum so i hope that it would be helpful :
i dont really understand what you are trying to accomplish with what you asked for but here is what im thinking you are trying to do is to make a custom shape for each of the page number
if that what you want there is 2 way i can think about them at the moment
first we will make our pager i assume that you have don it already.
then we will go and create a variable thats contains the number of pages
and watch the (-1) to make the element index counted ;
then we will create a for loop for handle the anchor elements of the pager
and within this for loop we will change the css background value for each element .
and now all what you have to do is to create the folder image/pager and then put there your images for the pager and name them
pagenumber(the page number).png
and dont forget to change the css value for the activepage
and the other way is like this one you will change the contents of this element (the anchor) to an img value without have to change any css background for each page
if there is some thing that you dont get it please let me know