Question installing commercial SSL cert

I have a commercial Geotrust cert of type: Apache + MODSSL

is-it possible to install this in Tomcat?

There doesn't seem to be a simple howto or doc for that, I only found the procedure to create self-signed ones.

Not being very familiar with Tomcat it is hard to be sure that I follow the proper way of doing things. Analysing zmcreatecert it seems kind of a black art!

I tried to modify directly:
/opt/zimbra/tomcat/conf/server.xml.in

I replaced in section for HTTPS:

keystoreFile="/opt/zimbra/tomcat/conf/keystore" keystorePass="zimbra"/>

by:

SSLCertificateFile="/opt/zimbra/ssl/ssl/server/mycert.crt"
SSLCertificateKeyFile="/opt/zimbra/ssl/ssl/server/mycert.key"/>

su zimbra
tomcat stop
tomcat start

but it does not seems to work.