Wild card ssl setup

[chartman]

Does anyone know how to set up wildcard ssl certificates in Plesk 7.5?

I have a root domain with variations like the following.

domain1.rootdomain.com
domain2.rootdomain.com
domain3.rootdomain.com

Each of the rootdomains is set up as a separate domain. I would like to use a wildcard certificate to provide ssl for each of the domains.

Haven't found any documentation on setting it up yet, but am still looking.

Thanks