If you go to the Scheduled Backups tab in Reflect You can edit the program that is run. look for the VBMAIN subprogram
Maybe I am stupid, but no idea where to find this (especially as I use the German version).
The only thing I see in the "Scheduled Tasks" is this:

Below are my entries for the scheduled tasks. When I select one, there are 2 tabs at the bottom "Backup Options" and "XML View".
In the backup tab itself I have this, with 2 icons about VBscript.

But we would need to know how you access your NAS
Either with IP 192.168.178.31 or \\SERVER_DS ... if that is what you meant. I would create two folders e,g. "1" and "2" inside \\SERVER_DS\homes\timo\Backups where I would copy a dummy file from folder 1 to 2.
Windows 8.1 Home/Core x64, Macrium Reflect Home v6, Synology DS115 with DSM 5.2