So you added a token in the NS at
Settings | Deployment | Tokens
You called it JOBUSER and you'd like the SQL used to get the JOBUSER to put into the Job.
Did you leave it blank currently?
Example
NS Server name
/*** A token to return the NS server name ***/
/*** %NSSERVER% : Returns NS server name ***/
select [Server] from [dbo].[vComputer] where [Guid] = '%COMPUTERID%'