I doubt there is an "application" to do what you want since the edit s/b pretty easy. I do not use SARG but have done a similar edit for other applications.
All you need to do is edit the source file that is generating the report page, comment-out the SARG hyperlink, copy and paste that line below|above the original, replace the SARG link with your own in the copy, check it for accuracy and then remove the comment marks on the new line you just made.
It is just HTML ... there are at least 52 other ways to accomplish the same thing. (E.g., just add your own logo and link beside/under/over the SARG logo ...).
If you do not know what is the source page for the link, try "View Page Source"(via right-click in Ffx) for the report page and it should lead you to it.