Get or convert a queries from TFS to WIQL to use with the TFS API (not Webservices)

I'm trying to get the data returned by the next querie launched from Visual Studio Team Foundation Server through a small program made in C #. While I manage to get the workitems on one hand, I would like to move the next one using the Microsoft.TeamFoundation.Client libraries. and Microsoft.TeamFoundation.WorkItemTracking.Client

I found the following link but I do not finish right with the "adaptation".

Retrieving TFS results

Could someone help me?

Thank you very much.