Click on a control in the open form to select it and then select Copy in the Edit menu to move a copy of the control to the clipboard. Alternatively, you may simply right-click the mouse on the control and select the same Copy function from the pop-up menu.
Now move back to the Editor window. Move the cursor to the position where the control name is to be inserted. Select Paste in the Edit menu to place a copy of the control name at the cursor position. Alternatively, you may right-click the mouse anywhere in the Editor window and select the same Paste function from the pop-up menu.