How to create a relative shortcut ?

Hello all,

I'm trying to create relative shortcuts* (for use on a removable USB 
harddisk) and can't seem to find out how it works.

* the target of the link is relative to the location of the link itself.

I'm programming against the IShellLink interface ( 
https://learn.microsoft.com/en-us/windows/win32/api/shobjidl_core/nn-shobjidl_core-ishelllinka) , 
which suggests a relative path is possible (SetRelativePath), but I'm not 
able to get it to work or find code explaining how to do it.

I did find this : 
https://devblogs.microsoft.com/oldnewthing/20171019-00/?p=97247 , but I'm 
not even sure if that is what I'm after ... :-|

Question: does someone have an example to what I'm supposed to do to make it 
happen ?

Regards,
Rudy Wieser