Does the A320 DIR on the MCDU work?

DIR TO does not work.

However, you can go to the PROG page and enter a waypoint in BRG/DIST TO [-----].

So you will have the bearing to this waypoint. And then select the value as heading in the FCU.

The bearing will change as much as the aircraft is turning so the heading will have to be adjust.

It is not elegant at all.

Please, note that some waypoints will not be found in the MCDU (even the nearest ones or the nextdoor points). They can't be found in the PROG page, neither in the F-PLN page, etc.