How to output std::cout from multiple applications to one window (console)?

Question

Programming

There is a program (Qt) that outputs debugging information to std::cout.
There is another program that catches text coming from the USB HID and redirects it to std::cout.
How to merge the output of these 2 programs into one console?
Everything can be rewritten, output where necessary, using the capabilities of Qt. But how is it easier and where?
OS: Windows 7

Answer 1

Run both processes from a third program and intercept the output of both, the OS supports this.