Change the extension inside the file

[loopingz]

I use to download file like test.rar.ext with a sfv type test.sfv.ext
It would be great to create a new (or to modify directly) sfv by changing inside the name from test.rar to test.rar.ext. Because i cant rename my archive *.ext before the end of the download...
don't know if you understand me but thanks anyway for this software !