There is only one version of CCE 2.5. It is both the stand alone and the pluggin in the one program. When you run the CCE.REG file, its adds into the registry that you have Premier installed. You dont need Premire and you dont need to install it, the cce.reg file fixs all that for you.
When you then install CCE, the option to install the plugin ins now highlighted, slect it. Just point the pluggin to the Flask folder. After installation go to the Flask folder and there will be new file with a name similar to cce-mpeg-cm.prm or whatever. Thats the file to rename to cce.cm.flask
Cheers.