Convert::ASN1 example needed

[<vi...@al...>]

Hi all,

I would like to decode an ASN.1 string. In this string a digital
certificate is stored.
I'm able to retrieve the userCertificate attribute value from
the Directory server, but I still don't know how to decode the
ASN.1. The only thing I need is the creation timestamp of the
certificate. I looked at the Convert::ASN.1 library, but I don't
know how to use it.
http://search.cpan.org/doc/GBARR/Convert-ASN1-0.07/htdocs/Convert/ASN1.html

Maybe somebody has a another example how to decode ASN.1 in Perl
with Convert::ASN1?

Thanks!
Vincent.