D.T.
Many of our friends have home-schooled their children from kindergarten through high school due to their frequent moving due to the government.
They have always registered their children with the local school system, and had them tested at the beginning of the year, mid-year, and at the end of the year to ensure that they were on task, and registered their grades with the local school system. This way they are able to maintain their children's progress and their GPA.
In the past, you have been able to register your children at the local high schools and allow them to take course work that is not available in the home school cirriculum, and to have social interatction and to belong to clubs: Key, Anchor, Civics, etc.
I hope that this helps you.