Here are some contrib files that might help you.

putty-smartcard.patch.gz
	Patch for putty itself (windows ssh program).
pageant-smartcard.patch.gz
	Patch for pageant (putty/windows version of the ssh agent).

	The patch currently uses the opensc pkcs11 library, so this will
	only work with opensc installed.  Pageant will attempt to load
	the pkcs11 library if tell it to get a key from the included
	smartcard_key_file.ppk.  This can be extended to load a specific
	key or a different library without a great deal of effort, but
	currently it just loads the first key from the first card that
	the opensc pkcs11 library finds.

	For feedback please contact: Kevin Stefanik <kstef@mtppi.org>

A second efford to use smart cards with putty was donated by Peter Koch:
PuTTYcard-1.0.zip
	A patched putty/pageant version so it can load a library with
	key/crypto functions, e.g. to use the key of a smart card.

PuTTYcard-1.0-src.zip
	Source code for the above. Licensed under the same license
	as putty itself.

	For feedback please contact: Peter Koch <opensc.pkoch@spamgourmet.com>

PuTTYcard-1.0-DLL.zip
	An improved library for the above, implementing access to
	keys on TCOS smart cards. Unfortunatly this library comes
	as binary only without source code, and is available for
	non-profit use only (i.e. inhouse, non-commercial academic
	and research purposes only, without a fee).

	For feedback please contact: Peter Koch <opensc.pkoch@spamgourmet.com>