FarPoint.Web.Spread.Model.IExpressionSupport ems;
FarPoint.CalcEngine.Expression one = new FarPoint.CalcEngine.DoubleExpression(1.0);
FarPoint.CalcEngine.Expression two = new FarPoint.CalcEngine.DoubleExpression(2.0);
FarPoint.CalcEngine.Expression oneplustwo = new FarPoint.CalcEngine.BinaryOperatorExpression(FarPoint.CalcEngine.BinaryOperatorInfo.AddOperator, one, two);
ems = (FarPoint.Web.Spread.Model.IExpressionSupport)FpSpread1.ActiveSheetView.DataModel;
ems.SetExpression(0, 0, oneplustwo);
Response.Write("The type of expression is " + ems.GetExpression(0, 0).ToString());