The function you need is in the Transparent Commands toolsbar.
If the toolbar isnt showing, click on the View Tab, User Interface Panel (far right hand side), click on Toolbars, go down to Civil and tick on Transparent Commands.
When this Toolbar comes up on the screen, the function you want is the Point Number.
Steps to get it to work are:
1. Start either the Line or Polyine command
2. Select the Point number icon in the Transparent command toolbar (8th from the left) or type in ‘PN in the commandline
3. Then start typing in the numbers you want to join
4. Continue typing the numbers if you want them all to be joined. If you want them to be separate lines/polylines then you have to start and stop the line/polyline command each time
5. Points are now joined by typing a Point Number in.