If you generate the report directly to your web site then the Source URL target files or copied over and can be accessed from the report without further action. But if you generate to a local folder first and then copy the report to your website then perhaps the problem you report could arise.
If you want to pursue the Find & Replace approach then you can export your .gno to XML then use a text editor to perform the search and replace. Then reopen the edited XML file with GenoPro and save as a .gno again.