How to encode a custom certificate extension?

From: Dan (dan110911_at_yahoo.com)
Date: 05/25/04 

Date: Tue, 25 May 2004 11:01:03 -0700

What is the best method to get custom information into a certificate (using CCertAdmin, CCertEnroll, or something else)? For example, if I wanted to put employee ID (int or string) information into a certificate, not using Subject but some other new OID which doesn't already have a structure associated with it, what could be done? I've been able to get partial results, but keep coming across strange ASN.1 encoding issues.