Yes I had used \\ but not put it all in quotation marks, now working fine. Thanks for your help.

I have Dosbox and the DOS programs in a directory on a Synology NAS drive. The combination works fine if I map the drives to letters Y and Z but I have do this every time before I can use Dosbox. I cannot mount the drives either by their network names or IP addresses presumably due to the 8.3 dos …