..
//didn't have this component so I had to look for how to download...ide->menu Setup->UppHub  and select Functions4U
//in the declaration
#include <Functions4U/Functions4U.h> 
...
Dl screen;
void (*yF)(int x, int y, int cx, int cy, char *filename);
...
//AA is my class with method below
// integer n is saves lives 
//lifeguards that I had to adapt because
//the link https://www.ultimatepp.org/src$Functions4U$Dl$en-us.html 
//that exemplifies on windows will fail (bug?) if it [b]loads repeatedly[/b]

void AA::clickDll(){
	if(n==0){
		
	   if (!screen.Load(AppendFileName("C:\\Temp\\outU++\\NOVOXXX\\CLANGx64.Debug.Debug_Full.Gui", "CaptureScreenDll.dll")))
              throw Exc(Format(t_("% dll not found"), "Capture"));
	
           yF = (void (*)(int,int,int,int,char *))screen.GetFunction("capture_screen");
 
	}
        if (!yF)
           throw Exc(Format(t_("Function %s does not found in dll"), "captureScreen"));
 
        char* f="teste.png";
        yF(669,187,420,22,f);
     
        n++;

}

...
typedef void (*importFunction)(int, int, int, int, char *); 
...
void AA::clickDll2(){
	importFunction fscreen;

	HINSTANCE hinstLib = LoadLibrary(AppendFileName("C:\\Temp\\outU++\\NOVOXXX\\CLANGx64.Debug.Debug_Full.Gui", "CaptureScreenDll.dll"));
 	if (hinstLib == NULL) {
 		PromptOK("ERRO: não foi possível carregar a DLL\n");
 		return;
 	}	
 	fscreen = (importFunction)GetProcAddress(hinstLib, "capture_screen");
 	if (fscreen == NULL) {
 		PromptOK("ERRO: não foi possível achar a função na DLL\n");
                //FreeLibrary(hinstLib);  uncommenting will abort here
 		return;
 	} 	

 	char* f="teste2.png";
    fscreen(0,0,500,600,f);
    
    //FreeLibrary(hinstLib); uncommenting will abort here
	
}

			static BOOL (WINAPI *GetPointerPenInfoHistory)(UINT32 pointerId, UINT32 *entriesCount, POINTER_PEN_INFO *penInfo);
		
			ONCELOCK {
				DllFn(GetPointerPenInfoHistory, "User32.dll", "GetPointerPenInfoHistory");
			};

#if defined(PLATFORM_WIN32) 
	HINSTANCE hinstLib = 0;	
#else
	void *hinstLib = 0;
#endif