Kite, it is actually quite easy to do what you want when you know how... And almost impossible when you don't!
Setting And Saving ABRIS Routes In BS2
The ABRIS is able to save routes and other information to an internal hard disk, within the DCS simulator. This is lost when you exit each mission. However, there is one exception; when you have entered the simulator through the Mission Planner, the data is preserved and can then be saved within the .miz file. Once saved, you can return to the cockpit as many times as you like to fly the mission as normal with your saved ABRIS data.
To plan routes and have them available for later use, you do the following:
Open your mission in the mission planner/editor and load the simulator from there by selecting Flight > Prepare Mission from the drop down menu.
Create, edit and save one or more routes in the ABRIS.
Instruct the ABRIS to save all routes to its hard disk.
Quit the mission preparation, automatically returning to the mission planner.
Save the mission file within the mission planner.
Optionally rename the mission file to zip and edit lua files manually (returning it to .miz afterwards).
When returning to the cockpit, load one of the saved routes.
The .miz file can be renamed to .zip and browsed, or opened using software. Within the file, you will find ABRIS data stored in the folder ABRIS\Database. You can open the 3 lua files and edit them. The files are:
ROUTES.lua: stores routes that were saved within the ABRIS.
NAVIGATION.lua: stores the 'objects' that the ABRIS displays, such as NDB beacons, airfields and no doubt many other things.
ADDITIONAL.lua: doesn't seem to store a great deal. Perhaps this is where you could add in additional 'objects' that are relevant to a mission, perhaps a rendezvous point or something.
Being able to edit the ROUTES.lua is something which I think could prove very useful. For example, this provides a much easier way of naming your waypoints compared to spinning and pushing the little ABRIS knob!
I have a problem where in the mission planner, the menu itself is sometimes not visible until I have selected several objects and clicked the blank space above the map where I would expect to see the menu header.
When saving a mission in the mission planner, the 'save' button may not always work so use 'File > Save As' to be sure you have saved your changes.
Note that this process alters the .miz files, I recommend you copy the entire contents of the original missions folder under Program Files to your %userprofile%\Saved Games folder. One of the great improvements in BS2 is the use of the Saved Games folder I think.
This youtube video helps but in my experience is not completely accurate:
http://www.youtube.com/watch?v=HqdZ_mkrtmU
To save routes in the ABRIS (step 2):
From the menu page, click PLAN.
From the plan page, click SELECT and choose SAVE.
Name the file and save it.
To save all routes in the ABRIS (step 3, shown at 3:38 to 3:58 in the video):
From the menu page, click CTRL
From the control page, click SETUP, choose DTB.
Press SAVE, scroll down to the line with 'ROUTES' and check there is a number of routes shown.
Press SAVE again.
To load routes in the ABRIS (step 7):
From the menu page, click PLAN.
From the plan page, click SELECT and choose LOAD.
Select the file and load it.
From the plan page, click ACTIV.
In my experience, contrary to the caption at the end of the video, this does not make the saved routes available in all missions. I also agree with previous posts that this will only work done through the mission planner.