Deploying authenticode certificates using GPO's

Hello all,

I have a vendor Authenticode certificate that I need to assign to a users
session when they logon onto specific workstations.

I have a win2k AD domain and under the user configuration\windows
settings\internet explorer maintenance\security of the policy, I set the
Authenticode setting. In side this setting I set the import option and
browse to select the certificate. But once here the box is listed as trusted
provides and doesn't give me the option to import the certificate.

I believe I may be approaching this wrong, could someone tell me how to get
the certificate listed in the trusted providers list or if this is even the
right approach.

Thanks in advance.

Roger