CADWorx Plant I tab: LNum > Count 
Line Number toolbar: Count
Plant menu: Accessory > Line Numbers > Count
Command line: NUMBERCOUNT
Sets the present line number count value.
This option requires that you set the LineNumberSystem variable to 1. This is the same as selecting the System On (Dynamic Size/Spec) option in the Line Numbering System dialog box. For more information, see Line Numbering System Dialog Box.