For the other new kids like me: an explanation below.
For the advanced Archicad users: This the best way of doing it?
1) Hover on the on side of the wall portion/door frame until the select circle shows.
9) Hover on the center of the window and wait for the select circle to show up.
Now you can drag the window to the center of the wall section.
This is how I do it. These operations can seem complicated when spelled out step-by-step, but ar very quick when internalized, so done without thinking about each step.
1. Select the Window Tool, and have the desired window set up.
2. Have the Snap Points set to Half (I have the Control Box visible in my Workspace Scheme for accessing this setting, but it remains on Half 95% of the time).
3. Use the keyboard command for Snap Point Constraint (if you do nit currently have a keyboard shortcut for this command, create one in your Work Environment).
4. Click on the corner, then click on the jamb of the door, the Window appears at the midpoint.
5. Click on the outside side of the Wall.
The Window is placed halfway between the corner and the door jamb. After having the correct Window set up in the Window Tool (which could be set up by option-clicking on an existing window with the correct settings) this is a four step operation without waiting for a temporary snap point to appear, about one or two seconds.