To perform that use case -- you will need to perform several tasks:
1 - write application logic using a Java API to read data from the CVS repo. I suggest using an API like this: http://javacvs.sourceforge.net.
2 - next when you get the Java working - you need to place the application logic into an OSGi bundle. This represents a custom AEM service.
3 - Deploy the bundle.
If you are not familiar with how to build OSGi bundles - see this community article:
http://helpx.adobe.com/experience-manager/using/first-osgi.html
Here is an example of building a custom AEM Service that is able to import data into AEM from Excel - it gives you an idea of how to build a custom service that imports data:
http://helpx.adobe.com/experience-manager/using/creating-custom-excel-service-experience.html
In your use case - instead of using the Excel Java API - you will use a Java API that can import data from a CVS repos.
