Keep Progress Bar from resetting to 0?

I have a progress bar in my course, up at the title level. I'm using the custom Progress Bar with a range of 26 (number of pages in course) and a step size of 1. I have four lessons in my course, and after each lesson I force the user to a Course Menu which is the first page in my course, where they can then pick the next Lesson to start.

Lesson 1 - 4 pages

Lesson 2 - 11 pages

Lesson 3 - 6 pages

Lesson 4 - 5 pages

At the end of Lesson 1, I have an action On Show Set Progress to Position 4. At the end of Lesson 2, I have an action On Show Set Progress Bar to Position 15, etc. This part works fine, but when the student is sent back to the Course Menu (page 1 in my course) the Progress Bar resets to 0. So I added a variable to the end of each course (at the end of Lesson 1 set my variable Lesson1Done to 11, at the end of Lesson 2, set my variable Lesson2Done to 22, etc.) and added actions to the Course Menu, If Lesson1Done equals 11, set progress bar to 4, If Lesson2Done equals 22, set progress bar to 15, etc. But this doesn't seem to work. My progress bar still resets to 0 when the student goes to the Course Menu.

How can I keep the progress bar from going back to 0, and retain the student's progress?

Thanks for your help!

Sandra