(From idx In Enumerable.Range(0,dtData.Rows.Count)
Where dtData.Rows(idx)(YourColumnNameOrIndex).toString.Trim.StartsWith(YourFilterString)
Select idx + YourOffset).toArray
here you got the template, are your replacing all the values from your values? like column name, you dt variable, filter
and remember after that to get youroffset which is explained here