How can I control what the tower and emplacements attacks?

Question

How can I control what the tower / emplacements attacks? You can do this with normal units by selecting one, and hit on the target.

Answer 1

You can't. The towers are auto-targeting.

You can put sensor towers where indirect weapon fire should impact. The weapon will automatically controlled by the sensor tower, and fire at targets in the sensor´s line of sight (and within the weapon´s reach).