I want to come out the back of a spigot at a 90 degree angle - e.g. from this
To this
However, when you screw the two all the way together, you'll end up with a (seemingly?) arbitrarily oriented elbow. That is, say for example a pipe was coming up from the bottom, but when you screwed the elbow to the spigot the elbow ended up pointing up, which wouldn't work.
It would seem reasonable to be able to control the direction that you come out,
How would you do this?