How can I redirect my Pen-Input to Mouse-Input?

Question

Here is what I want to do: My Pen should act as my mouse when I put it on my screen. When I put it onto the screen, move it, and lift it, my device should think I pressed the Left mouse button, moved my mouse, and let go.

I have done some research, and it seems like this should be a start. But I don't get what exactly I have to do. I have some experience from coding in Visual Studio, and already made some UWP programmes, but I cannot find out what I have to do to get this working.

Even after intensive googling, I cannot find out what this page wants from me. I get that I need to find some kind of DLL, but even this code block:

HOOKPROC hkprcSysMsg;
static HINSTANCE hinstDLL; 
static HHOOK hhookSysMsg; 

hinstDLL = LoadLibrary(TEXT("c:\\myapp\\sysmsg.dll"));  
hkprcSysMsg = (HOOKPROC)GetProcAddress(hinstDLL, "SysMessageProc"); 

hhookSysMsg = SetWindowsHookEx( 
                WH_SYSMSGFILTER,
                hkprcSysMsg,
                hinstDLL,
                0); 

is too much for me and I can't find out where to paste this. Clearly, pasting it into a new UWP or WPF project isn't enough, which was what I have been doing until now. I know this is way more complicated than I can handle, so I hope you can quickly help me out just by telling me where I am supposed to paste the code into, and where I can get the sysmsg.dll