Using AT command for backups

Hi,
I’m trying to schedule automatic backups using the AT command. The schedule service is started and set to automatic. I’m typing in the following command but having no luck.
AT 1 20.00 /every:Monday,Tuesday,Wednesday,Thursday, “incre.bat”Can anyone tell what is wrong with this line or can anyone suggest a proper working AT command line. I dont have access to Winat. Thanks.