Just execute the following as a batch file.
regedit /e %homepath%\Desktop\puttyexport.reg HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\Sessions
This creates a .reg file on your desktop. Import it into the target PC to transfer settings.
If you need to sync with Dropbox:
regedit /e %homepath%\Dropbox\Putty\puttyexport.reg HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\Sessions
Joel G Mathew, known in tech circles by the pseudonym Droidzone, is an opensource and programming enthusiast.
His favorite pastime is grappling with GNU compilers, discovering newer Linux secrets, writing scripts, hacking roms, and programs (nothing illegal), reading, blogging. and testing out the latest gadgets.
When away from the tech world, Dr Joel G. Mathew is a practising ENT Surgeon, busy with surgeries and clinical practise.