Could do something like this:
(f2 denotes a form instance, sloppy, but its late)
System.Windows.Forms.TextBox[] x = new System.Windows.Forms.TextBox[15];
x[1]= new System.Windows.Forms.TextBox();
x[1].Visible = true;
x[1].Top = 100;
x[1].Left = 100;
x[1].Parent = f2;
x[2] = new System.Windows.Forms.TextBox();
x[2].Visible = true;
x[2].Top = 130;
x[2].Left = 100;
x[2].Parent = f2;
x[3] = new System.Windows.Forms.TextBox();
x[3].Top = 160;
x[3].Left = 100;
x[3].Visible = true;
x[3].Parent = f2;
etc..........