Following is the the C# version of the solution given by"Ratnesh Rai" with minor changes.
string formtocall="frmMyForm";
System.Reflection.Assembly myAssembly = System.Reflection.Assembly.GetExecutingAssembly();
Type[] types = myAssembly.GetTypes();
foreach (Type type in types)
{
if (type.BaseType.FullName== "System.Windows.Forms.Form")
{
if (type.Name==formtocall)
{
var form = Activator.CreateInstance(Type.GetType("YourNamespace." + formtocall)) as Form;
form.ShowDialog();
break;
}
}
}