Multiple inheritance workarounds?

 
I'm studying OOP and I've come across the following problem. I use a class based on CAppDialog to build the interface. CDialog -> CAppDialog -> CfxwAppDialog. I want to change the appearance of the m_caption element. The m_caption element and the CreateCaption method belong to the CDialog class and the m_caption element is private. And I still want to use the CAppDialog class in an unchanged form. I want to avoid copying the entire CAppDialog class to get inheritance: CDialog -> CfxwDialog -> CAppDialogCOPY -> CfxwAppDialog. I also do not want to change the standard library. Is there, given the fact that there is no possibility in mql for multiple inheritance, any other way to do it, except for forking, to get the effect I want?
 
https://www.mql5.com/en/docs/standardlibrary/controls/cdialog/cdialogcaption
Documentation on MQL5: Standard Library / Panels and Dialogs / CDialog / Caption
Documentation on MQL5: Standard Library / Panels and Dialogs / CDialog / Caption
  • www.mql5.com
Standard Library / Panels and Dialogs / CDialog / Caption - Reference on algorithmic/automated trading language for MetaTrader 5
 
Yes, I noticed these methods, but by appearance I meant color, font, font size etc. Not text.
 
Marcin Madrzak:
Yes, I noticed these methods, but by appearance I meant color, font, font size etc. Not text.
Oh...you'll have to fork it. It's unfortunate that they didn't make those protected.
Reason: