m2tklib and openGLCD

Hello,
I am building GUI for my project with 128x64 graphic lcd with help of m2tklib library. I made my custom PCB with atmega644 and Sanguino configuration for Arduino. I migrated my project from Arduino IDE to Atmel Studio with Visual Micro extention, because I have multi-file project and I have more control over my project with this approach.
At first, I was using u8glib library for graphic handling, but it turned out, that it was too slow. All button reactions and drawing functions was really slow and I didn't like that. So I decided to try out GLCD library, which m2tklib also support. And then I found, that GLCD is obsolete and there is new, improved library, which is compatible with GLCD - openGLCD. So I gave it a shot. I am using it in compatibility mode with GLCDv3 and I must say, that this library is rocket fast in terms of drawing and button reactions oposing to u8glib. All good. But now the issue:
I made some bitmap hex arrays for my application and I was using them successfully with u8glib and m2tklib with elements M2_XBMLABELB, M2_XBMBUTTONP, M2_XBMROOTP. But these elements are supported just from u8glib and I really need those elements for bimaps to be displayed on my lcd, because I included them in some other elements like HLIST and VLIST and ALIGN and should be displayed on particular menus.
I tryed to create bitmaps with included java program in openGLCD library and I successfully created .h files with hex arrays for these bitmaps. Then I used these created arrays with M2 elements for bitmaps (M2_XBMBUTTONP and others). Program was compiled succesfully, but then my LCD just displays empty boxes instead of bitmaps. This was expected, because m2tklib xbm elements only support u8glib. Now my question is, how can I display those bitmaps with these elements? I can't use GLCD.drawBitmap function directly, because I need to display those elements in combination with other elements of m2tklib library.
For example, this is my declaration of some button with M2_XBMBUTTONP element:

M2_XBMBUTTONP(el_button_potrdi,"w48h18",48,18,ikona_ok,fn_potrdi);

and ikona_ok is defined in ikona_ok.h file in bitmaps directory of openGLCD library.

I hope I was clear about my issue and I am sorry if my writing is cumbersome.

Thank you for all answers.