certadmin and certtool are different utilities, so no you can't use expressions from one for the other.
It looks like certadmin is only present if you have the Apple server software (now called Server.app) if you don't have Server.app installed this explains why you cannot find this tool.
Update: I have checked my Mountain Lion server and certadmin is located at the following location
Thanks! I found it. BUT still there are som issues for profilemanger with the ssl. It cant load enrollment to Mac clients.
I search and found that the Intermidiate ssl needs repair. (My system are a clean install and OD archive imported.)
With you solution i get this when script is halted;
"/Applications/Server.app/Contents/ServerRoot/usr/sbin/certadmin Cannot find the certificate: ns.ostraserver.se Code Signing Certificate"
But still i have the sam intermidiate ssl cert that looked the same as previous installation. I is valid trough 2014.