How to handle events from embedded Excel.OleObjects or Excel.Shapes

Have you tried using NewLateBinding.LateGet?

using MSForms = Microsoft.Vbe.Interop.Forms;using Microsoft.VisualBasic.CompilerServices;...MSForms.CommandButton CommandButton1 = (MSForms.CommandButton)NewLateBinding.LateGet(Globals.ThisWorkbook.Worksheets(1), null, "CommandButton1", new object[0], null, null, null);                CommandButton1.Click += new Microsoft.Vbe.Interop.Forms.CommandButtonEvents_ClickEventHandler(CommandButton1_Click);

It's referenced on MSDN in the VSTO forums and in an old blog post.

Solution Type: VSTO Document-Level

Scenario:
1.) Excel.Worksheet created at run-time. (not a Worksheet Host Item)
2.) Add a button on the Worksheet at run-time that triggers C# code when clicked.

Assembly References:
Microsoft.Vbe.Interop (Microsoft.Vbe.Interop.dll)
Microsoft.Vbe.Interop.Forms (Microsoft.Vbe.Interop.Forms.dll)
Microsoft.VisualBasic (Microsoft.VisualBasic.dll)

Tested / Working Code:

using MSForms = Microsoft.Vbe.Interop.Forms;using System.Windows.Forms;...Microsoft.Vbe.Interop.Forms.CommandButton CmdBtn;private void CreateOLEButton(){   Excel.Worksheet ws = Globals.ThisWorkbook.Application.Sheets["MyWorksheet"];   // insert button shape   Excel.Shape cmdButton = ws.Shapes.AddOLEObject("Forms.CommandButton.1", Type.Missing, false, false, Type.Missing, Type.Missing, Type.Missing, 500, 5, 100, 60);   cmdButton.Name = "btnButton";   // bind it and wire it up   CmdBtn = (Microsoft.Vbe.Interop.Forms.CommandButton)Microsoft.VisualBasic.CompilerServices.NewLateBinding.LateGet(ws, null, "btnButton", new object[0], null, null, null);   CmdBtn.Caption = "Click me!";   CmdBtn.Click += new MSForms.CommandButtonEvents_ClickEventHandler(ExecuteCmd_Click);}private void ExecuteCmd_Click(){   MessageBox.Show("Click");}

Can you programmatically add code to a CodeModule in the Workbook, like this?

Private Sub CommonButton_Click(ByVal buttonName As String)  MsgBox "You clicked button [" & buttonName & "]"End SubPrivate Sub CreateEventHandler(ByVal buttonName As String)    Dim VBComp As VBIDE.VBComponent    Dim CodeMod As VBIDE.CodeModule    Dim codeText As String    Dim LineNum As Long    Set VBComp = ThisWorkbook.VBProject.VBComponents(Me.CodeName)    Set CodeMod = VBComp.CodeModule    LineNum = CodeMod.CountOfLines + 1    codeText = codeText & "Private Sub " & buttonName & "_Click()" & vbCrLf    codeText = codeText & "  Dim buttonName As String" & vbCrLf    codeText = codeText & "  buttonName = """ & buttonName & "" & vbCrLf    codeText = codeText & "  CommonButton_Click buttonName" & vbCrLf    codeText = codeText & "End Sub"    CodeMod.InsertLines LineNum, codeTextEnd Sub