Days ago I discovered portable putty...
The first problem I found was that I didn't have de psftp on the portable edition... So I just copied de .exe from my NON portable version of putty...
Firstly I thought it wouldn't work, but when I went to another PC that didn't have puttys intalled, and I start putty portable edition (just turn on, without login in any session) and start as well the psftp (copied from my PC .exe) an then typed open "my connection"
(where my connection is the name of my current connection prevously saved on putty portable edition) and IT WORKED!
Provably you knew it... or maybe not because I see that you have done another portable app that lets make sftp connections intead of ussing psftp...
Well, I wish I haven't posted this in a wrong forum...
Thanks for listening reading me and sorry for my bad english