move comodo certificate from send mail server to zimbra server

we wish to transfer mail system from sendmail to zimbra mail. we have comodo certificate in send mail. we want to move it to zimbra server.
the same domain name , but the hostname of the server different . is it possible to that. and if it possibe how do deploy that

You should be able to export the private-key and certificate from the sendmail system, and import that in the zimbra server.

Here is a link to an example:
http://www.madboa.com/geek/openssl/#cert-pkcs12