alejandro, I have also done a Foxycart / PW integration.
This took me quite a while to get my head around too.
Quite simply, it doesn't matter which hashing method you choose in FoxyCart (I chose sha256)
This was my setup:
1. customer registers in FoxyCart
2. customer pays and datafeed is sent back to PW
3. password in datafeed is already sha256 so I just create a new user in PW with the already hashed password.
4. new PW user is setup which has a password which is sha256 hashed THEN PW hashed.
If you are setting up a login form where this user can login to PW, all you have to remember is you must sha256 the entered password, and use that in the $session->login call
Hope that is all clear
OK I feel like a n00b now!
This simple bit of code seems to work anywhere in the front-end:
if ($this->modules->isInstalled('ProcessForgotPassword')) echo $this->modules->get("ProcessForgotPassword")->execute();
Obviously it should be attached to a link and used in the same context as in the backend... but It generates the bare unstyled forms, and seems to handle all the functionality perfectly.