Flying on auto pilot. Descending to the Initial fix to an ILS. I want to go 15 miles in the opposite direction.
Let’s say the inbound course is 221. I enter Direct, type in the waypoint with course inbound 221.
I pull the heading to make it controlled by me instead of MCDU. No centerline appears on the PFD. I can see the waypoint initial fix. When it is time to activate, the A320 does fly an intercept course. I hit approach and the plane flies the ILS and even auto lands.
Am I missing a step to have the Extended Center Line drawn on my PFD?
Thanks
You “should” be able to go to the Direct page, select the IAF and then enter the course on the right hand side. This will draw a line to it on the course you have selected.
Once executed, it will also return to Nav mode and calculate an intercept of the course.
If you don’t want that (because you haven’t been cleared for the approach yet, for example), pull the heading again.
Now you can still select LOC or Approach mode and it will intercept normally…as it sounds like you have already experienced! 
I believe the course you enter will be the reciprocal of the final approach course.
It’s funny, I do it ten times a week and the habit is so ingrained that I have a difficult time remembering what the entries are labelled anymore.