Hello.
In the latest version of Logicity (1.6.0027) we have added this very logic.
In the command like you would write:
"C:\Program Files\SaberLogic\Logicity\Logicity Desktop.exe" "C:\<RRD file name and path>" DEVICE=<Your printer name>
If your printers name has spaces in it, you will need to put double quotes around it in the command line.
I hope this works for you!
-Devin