Creating and modifying a job

I really hope someone can help me with this: I've been struggling with it all day to no avail. We have a db user (batch: is only used in overnight processes) who has some rights, but not all, and as a result of this, the user cannot run the execute command. And now it needs to.

So we had the bright idea of getting batch to create a job to do what it needed to. But, of course, batch is the owner of the job, so the same rights issue occurs. So I thought about creating job using sysadmin, then letting batch modify it as it needs to (changing the run date, etc), but it looks to me like a job created by sa is 'invisible' to batch. Any update attempt is met with "The specified @job_id does not exist". If I create the job with batch, no prob, but that's not going to work for me.

Please, does anyone have any ideas here?