Where to enter OCSP URL?

I've been working on converting some local user accounts to use smart cards for login. I was able to get everything working by manually importing the CA certs but would like to configure the systems to go to our local windows OCSP for cert validation and CRL checking as I'd prefer not to manually import the certs. I've seen some configurations for the pam_pkcs11.conf where you set the following:

enable_ocsp=true
cert_policy = ca, ocsp_on, signature;

My question is where do you enter the URL of the OCSP so the system knows where to look?

For reference I used the following guides for getting this working in a test environment:
http://ryandlane.com/blog/2008/10/21/seamless-smartcard-login-with-pam_pkcs11-and-pam_krb5-against-an-active-directory-domain-using-red-hat-enterprise-linux-5-part-1/
http://ryandlane.com/blog/2008/10/24/seamless-smartcard-login-with-pam_pkcs11-and-pam_krb5-against-an-active-directory-domain-using-red-hat-enterprise-linux-5-part-2/

My systems are running RHEL 5.11 and I would eventually like to get this set up for our local ldap accounts as well but figured I would see if I could get it working locally first.