How to correctly set the value of a type variable with a fixed number of digits?

Question

Qt

I'm still trying to defeat types in the ActiveX connected to Qt.
There is a function that takes a type with a fixed number of digits:
This is how it seems to be described "64-bit number with 4 fractional digits".
Qt after dumpcpp set that it is qlonglong.
The question itself is how to write it down now? Tried

N = 2;  
qlonglong val = N * 10000;

but the function gives out that the output number is "20000".
Tell me, please, how then to be?

Answer 1

So, the debugger went through the guts of Qt - this, apparently, is a "Bug", not a "Feature".