Hi

1.create eventhandler in usercontrol as
public delegate void TextChangeHandler(int x)
2.Create Event in UserControl as
public event TextChangeHandler TextChangeEvent;
3.In UserControl on textChange event
Raise above event with parsed textbox value as

textbox_change(....)
{
 int Count=int.Parse(textbox.text); 
        if(TextChangeEvent!=null)
 {
  TextChangeEvent(Count);
 }
}

4.In ur form add usercontrol and name it as uc1, inside panel panel1
5.Add handler as
uc1.TextChangeEvent+=new TextChangeHandler(myhandler);
.
.
.
public void myHandler(int s)
{
 for(i=0;i {
  MyUserControl cc=new MyUserControl();
  c.width=..;
  c.height=...;
c.left=..;
c.top=..;
  c.TextChangeEvent+=new TextChangeHandler(myhandler);
  panel1.controls.add(c);
 } 
}

Thats it.

Hope it helped.
Check this is correct answer