Experiment a little, most of these methods are similar in both the regular .NET controls  and Infragistics controls. If you check out the documentation, search for "Use WinDataSource at Run Time". There's some nice example code in that article.

UltraDataRow row;

// Get the first row. 
row = this.ultraDataSource1.Rows[0];

String somevalue = row["TheColumn"].ToString();

 I mean like in BindingSource we can use BindingSource.Current["Column"]

So, How to get value like that from UltraDatasource, not using UltraGrid.