LOL
There are two possiblities:
either you didn't explain your question very well, and I completely misunderstood.
OR
you didn't read the documentation very well...
check out ftp_rename...
You can rename a folderA who's path is /path/to/folderA to /path2/toanother/folderB
That's renaming... but it's also moving. Try reading more carefully.