I do not believe so. AFAIK the page number trails the content of what is pointed to. In other words, you can not break the string.

very very very very very very very very very very very very very very [break] page #
very very very loooooooooooong picture name

is not possible....I am pretty sure. ALL of the text is inserted, THEN the page number. I certainly would be interested if someone else knows how to split the content. It would probably be best to simply rename the long file to something more practical. I am no fan of hugely long names.