How to export the public key to a file

Hi, 
I have generated the key pairs using these codes (Ncryptoki.dll)
CryptokiCollection templatePub = new CryptokiCollection();             templatePub.Add(new ObjectAttribute(ObjectAttribute.CKA_CLASS, CryptokiObject.CKO_PUBLIC_KEY));             templatePub.Add(new ObjectAttribute(ObjectAttribute.CKA_TOKEN, true));             templatePub.Add(new ObjectAttribute(ObjectAttribute.CKA_PRIVATE, true));             templatePub.Add(new ObjectAttribute(ObjectAttribute.CKA_LABEL, "PUKey"));             templatePub.Add(new ObjectAttribute(ObjectAttribute.CKA_ID, "1"));             templatePub.Add(new ObjectAttribute(ObjectAttribute.CKA_MODULUS_BITS, 1024));
            CryptokiCollection templatePri = n ...