you cannot specify an ordinal in the eval/bind functions
the bind method takes the name of a data field and returns a string
containing the value of that field from the current record in the data source

public static Object Eval(
   Object container,
   string expression
)
container:
the object reference against which the expression is evaluated. this must be
a valid object identifier in the page's specified language.

expression:
the navigation path from the container object to the public property value
to be placed in the bound control property. this must be a string of property
or field names separated by periods, such as Tables[0].DefaultView.[0].Price

you could change the column name for your dataset2 to match the column name
of dataset1 before binding to the gridview control e.g.
DataSet2.Table[0].Columns[3].ColumnName =
DataSet1.Table[0].Columns[3].ColumnName
//bind to data source
DataGrid1.Bind();
//revert the change in dataset if the columnname is needed afterwards
DataSet2.Table[0].Columns[3].ColumnName = "OrgColName";