Editing features windows with the application "resource hacker", you can add that the window can be adjusted and activate the maximize button. It is easy to get.
The problem is that internal windows and buttons, not resized or adjusted to the new size you say.
I think you can not solve this problem by modifying only the style and ExStyle windows.
I think the function that handles these parameters is "Anchors" and I think you can not edit with any "resource editor".
Update
If there is a C + + programmer, you could create a simple window with a set button on the bottom right.
And also create the same window but without setting the button on the bottom right would.
Both windows with adjustable size.
See if comparing them easily with the app first Resource hacker and after watching the asm code we can see the difference in order to apply it to MapInstall.
I do not program in c + +, just a little Vbasic and I can not create two windows.