you'll need to be a bit more specific as to what you've tried and how it failed. i know this sounds a bit silly from your point of view, because that's what already failed. however, we need to get a bit more understanding on what you're trying to achieve, beyond the very brief description.
btw from all that i know, and i haven't used sftp perl module myself, i expect that the module will allow you to transfer files from a secure ftp server..and once transferred you can open and read them etc. for all i know the module just may let you read into scalar instead.
in any case, provide more information to get better answers. have you tested transferring the file(s) from the server to client just using a sftp client? how are you using sftp module to slurp remote file into scalar?
the hardest line to type correctly is: stty erase ^H