Hello,
Could you please tell us, using DOS commands do you want to create Automation Anywhere variable?
Automation Anywhere provides you an option that reads the variables from the text file. You can save the text file to be read on desktop so that the user, which is logged in can only use that file.
Go to Tools->Variable Manager and in 'User Variables' click on 'Add New Variable'. Select a variable of type 'List' or 'Value' (as per your requirement)and select the option 'Read from text file' and specify the file from where you would like to read the values from.
For better understanding, you can refer to following online example,
http://www.tethyssolutions.com/T12.htm
Hope that helps.