//Controls are added via the worksheets drawings collection. 
//Each type has its typed method returning the specific control class. 
//Optionally you can use the AddControl method specifying the control type via the eControlType enum
var dropDown = formSheet.Drawings.AddDropDownControl("DropDown1");
dropDown.InputRange = dataSheet.Cells["A1:A2"];     //Linkes to the range of items
dropDown.LinkedCell = formSheet.Cells["C4"];        //The cell where the selected index is updated.
dropDown.SetPosition(3, 1, 1, 0);                   //Set position to row 4 with 1 pixels offset and column 2
dropDown.SetSize(453, 32);

//Add a group box and four option boxes to select room type
var grpBox = formSheet.Drawings.AddGroupBoxControl("GroupBox 1");
grpBox.Text = "Room types";
grpBox.SetPosition(5, 8, 1, 1);
grpBox.SetSize(150, 150);

var r1 = formSheet.Drawings.AddRadioButtonControl("OptionSingleRoom");
r1.Text = "Single Room";
r1.FirstButton = true;
r1.LinkedCell = formSheet.Cells["C7"];
r1.SetPosition(5, 15, 1, 5);

var r2 = formSheet.Drawings.AddRadioButtonControl("OptionDoubleRoom");
r2.Text = "Double Room";
r2.LinkedCell = formSheet.Cells["C7"];
r2.SetPosition(6, 15, 1, 5);
r2.Checked = true;

var r3 = formSheet.Drawings.AddRadioButtonControl("OptionSuperiorRoom");
r3.Text = "Superior";
r3.LinkedCell = formSheet.Cells["C7"];
r3.SetPosition(7, 15, 1, 5);

var r4 = formSheet.Drawings.AddRadioButtonControl("OptionSuite");
r4.Text = "Suite";
r4.LinkedCell = formSheet.Cells["C7"];
r4.SetPosition(8, 15, 1, 5);

//Group the group box together with the radio buttons, so they act as one unit.
//You can group drawings via the Group method on one of the drawings, here using the group box...
var grp = grpBox.Group(r1, r2, r3);     //This will group the groupbox and three of the radio buttons. You would normally include r4 here as well, but we add it in the next statement to demonstrate how group shapes work.
//...Or add them to a group drawing returned by the Group method.
grp.Drawings.Add(r4); //This will add the fourth radio button to the group

var button = formSheet.Drawings.AddButtonControl("ExportButton");
button.Text = "Make Reservation";
button.Macro = "ExportButton_Click";
button.SetPosition(15, 0, 1, 0);
button.AutomaticSize = true;