If you look at "Predefined configuration item types" (http://www.symantec.com/docs/HOWTO93913) it says "You can also create new configuration item types, if required. However, Symantec recommends that you use predefined configuration item types, because different features and reports are available for the predefined configuration item types."
So you should examine this first:
"Adding a custom data class to a configuration item type"
After you create a custom data class, you can add it to a predefined configuration item type or to a new configuration item type that you create.
http://www.symantec.com/docs/HOWTO93234
If you don't think custom data class is enough see:
"Creating a custom configuration item type"
http://www.symantec.com/docs/HOWTO93228