How can I access pen pressure data on windows using rust?

Question

I need to access the pen pressure of windows stylus inputs similar to the libinput Tablet(Axis(_))-Event like I implemented here.

Since using libinput is a linux-specific library and doesn't work on windows, I tried using the RealTimeStylus-API using the windows-rs-crate.

After instanceating the com object with CoCreateInstance(&RealTimeStylus, None, CLSCTX_ALL), I ran into two issues:

1. If I try to use the SetHWND-Method to bind the window to the object, it needs a ::windows_core::IntoParam<super::super::Foundation::HANDLE_PTR>, not a HWND. While compiling, I get the following error:

error[E0277]: the trait bound `HWND: CanInto<HANDLE_PTR>` is not satisfied                                                                                               
    --> src\input\win_input_device.rs:43:40
     |
43   |             i_real_time_stylus.SetHWND(hwnd).unwrap();
     |                                ------- ^^^^ the trait `CanInto<HANDLE_PTR>` is not implemented for `HWND`
     |                                |
     |                                required by a bound introduced by this call
     |
     = help: the following other types implement trait `CanInto<T>`:
               <Battery as CanInto<IUnknown>>
               <Battery as CanInto<IInspectable>>
               <windows::core::imp::IAgileObject as CanInto<IUnknown>>
               <IAgileReference as CanInto<IUnknown>>
               <BatteryReport as CanInto<IUnknown>>
               <BatteryReport as CanInto<IInspectable>>
               <windows::core::imp::IErrorInfo as CanInto<IUnknown>>
               <ILowLevelDevicesAggregateProvider as CanInto<IUnknown>>
             and 452 others
     = note: required for `HWND` to implement `IntoParam<HANDLE_PTR, CopyType>`
note: required by a bound in `IRealTimeStylus::SetHWND`
    --> C:\Users\***\.cargo\registry\src\index.crates.io-6f17d22bba15001f\windows-0.51.1\src\Windows\Win32\UI\TabletPC\mod.rs:7079:13
     |
7077 |     pub unsafe fn SetHWND<P0>(&self, hwnd: P0) -> ::windows_core::Result<()>
     |                   ------- required by a bound in this associated function
7078 |     where
7079 |         P0: ::windows_core::IntoParam<super::super::Foundation::HANDLE_PTR>,
     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `IRealTimeStylus::SetHWND`

Trying to convert between the two types manually (i_real_time_stylus.SetHWND(HANDLE_PTR(hwnd.0 as _)).unwrap();) fails: The program just hangs indefinetly on the SetHWND Method.

2. To access events, I'd need to register an input plugin using AddStylusSyncPlugin (or the async equivalent), but the required interface is only provided as a struct, not a trait to implement.

Is there an easier way to get the current pen pressure? What am I doing wrong?

EDIT: After trying to build a minimal reproducible example, I noticed that the first issue was just caused by the way I got to the hwnd object:

let hwnd = HWND(<Win32WindowHandle>.hwnd as isize);
if !unsafe { IsWindow(hwnd).into() } {
    panic!("HWND is not a vaild window");
}

It works using GetActiveWindow. The second issue is still problematic...