I can query the page via IPageCriteriaQueryService interface with a criteria collection, any similiar interface to deal with the content?
The suggested option is to use EPiServer.Find to query for content.
Thanks for your fast response and I will give a try tomorrow.
Are you able to give me an answer of this question? http://world.episerver.com/Modules/Forum/Pages/Thread.aspx?id=71452&epslanguage=en