Question about locking panel borders

I'm writing an app where I want to have some buttons down the right side of the window, and a panel on the left side that resizes as the window is resized.

In other words, I want the area with the buttons to always stay the same size. Say, 64 units wide, but I want the right edge of the panel to the left of it to move so that as I resize the window, the panel changes size, and the right edge stays flush with the buttons, (which are always 64 units wide).

Is it possible to do this without manually resizing the panel every time the window changes size? If I remember correctly, the last time I tried to manually change the size of panels, it looked ugly when resizing because the app wasn't being refreshed by windows as often as windows refreshes the window size as you drag it.

Allowing panel edges to move on the other hand makes the changes smooth.

Whoops, nevermind, I am an idiot!

Of course, the help files are partly to blame as well.

Making an edge FREE means that the edge stays at the same coordinates all the time. It does not mean it is free to move about the country.

And LOCKING an edge means that the edge is forced to be a fixed distance from the equivalent edge of the gadget it is groped with. In the case of my panel, it is attached to the window, so if I "lock" it's right edge, the right edge will move with the edge of the window and remain a fixed distance from it.

Which is exactly the behavior I needed!