Can you access the file in that way from your PC – try typing the same thing in the address of a browser. I suspect that you need to map the shared folder as a network drive.
If you can access the file from your PC, then I think this should work.
Also, note that having it in /QDLS will bring problems. First, the /QDLS file system isn’t totally suitable for Win XP and is less suitable for each later Windows version. Also, it might not be supported by your version of Windows networking at all, though Microsoft did release some fixes that combine with IBM PTFs to make it possible for WinXP. I don’t know if anything after WinXP has decent fixes at all. IBM is unlikely to enhance /QDLS — use any of the more modern file systems instead.
Next, use of /QDLS requires entry in the system directory for whatever profile runs the network connection. A different file system wouldn’t have that requirement.
Next, the file system maintains DOS compatibility, including the 8.3 naming convention and (slow) access methods. A different file system wouldn’t have those restrictions.
In short, all use of /QDLS probably should have been converted to other file systems, e.g., /root, a decade or more ago.