C#

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
  switch (keyData)
  {
    case Keys.Control | Keys.Tab:
      // ... custom processing occurs hear.
      return true;

    case Keys.Control | Keys.F1:
      keyData = Keys.Control | Keys.Tab ;
      break;
  }
  return base.ProcessCmdKey(ref msg, keyData);
}

using System;
using System.Windows.Forms;

static class Program
{
    static void Main()
    {
        Application.Run(new Form1());
    }
}

class Form1 : Form
{
    public Form1()
    {
        menuStrip1 = new MenuStrip();
        fileToolStripMenuItem = new ToolStripMenuItem();
        openToolStripMenuItem = new ToolStripMenuItem();
        textBox1 = new TextBox();
        menuStrip1.Items.AddRange(new ToolStripItem[] { fileToolStripMenuItem });
        fileToolStripMenuItem.DropDownItems.AddRange(new ToolStripItem[] { openToolStripMenuItem });
        fileToolStripMenuItem.Text = "File";
        openToolStripMenuItem.ShortcutKeys = ((Keys)((Keys.Control | Keys.E)));
        openToolStripMenuItem.Text = "Open";
        openToolStripMenuItem.Click += new System.EventHandler(openToolStripMenuItem_Click);
        textBox1.Location = new System.Drawing.Point(55, 150);
        textBox1.ReadOnly = true;
        Controls.Add(textBox1);
        Controls.Add(menuStrip1);
        MainMenuStrip = menuStrip1;
    }

    void openToolStripMenuItem_Click(object sender, EventArgs e)
    {
        MessageBox.Show("Clicked");
    }

    MenuStrip menuStrip1;
    ToolStripMenuItem fileToolStripMenuItem;
    ToolStripMenuItem openToolStripMenuItem;
    TextBox textBox1;
}

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