Is it Possible to Write SQL Statement against Offline DataSet (there are no DataBase)

Hi every Body

I have a dataSet filled from XML file and no connection with any dataBase Engine

I need to make a join or group By or other things I need to use SQL features ?

when I make AddQuery It Ask for a connection and I have no

so how can I make Quries on my dataSet

I heard about LINQ but it is new for me ,

I am experinced with SQL Ad I want to know if there is any way to treat DataSet as DataBase and write SQL statement against it

thank you