1) Go to the supplementary waypoints editor and add a waypoint. These waypoints remain in your EFIS so you can reuse them.
2) Use the "Goto" function and choose "adhoc" waypoint. Enter the coordinates you want to fly to.
Alternatively, you can create your own navidata file using "MGL Central" offline. Here you can do what you want. You can use the resultant navidata file either as primary navidata file (you will probably use a "pre-made" primary navidata file such as the one available on the MGL Users forum, or a subscription product) - you can also use your own navidata file as a "secondary" navidata file. This will be loaded in addition to the "primary" navidata file so you can effectively "extend" your subscription product with your own private waypoints.
You can also use MGL Central to create a supplementary waypoint file for your EFIS (rather than creating it on the EFIS) - in that case you create a file called "waypoint.ewd" - simply copy that into your EFIS navdata folder using the built in file manager (overwriting the existing one).
Have a look at the PDF document "MGL EFIS Files" from our website (www.mglavionics.co.za) for a bit more in-depth on how things fit together on these systems.
