Cybersecurity

I have a servlet that is running a unix script on os390. The script is submitting a jcl using rexx to the mainframe. The mainframe is throwing an acf2id permissions error. It is saying that the job is owned by USTBATCH and will not allow permission to the pn files. Is there a way for me to change users before I do the submit. I know there is the 'expect' command, but our server doesn't support it. I wanted to do an su username, but cannot figure it out. Please help. How can I get around this or is there a better solution?

Thanks,

Justin Mennen

Even the craziest ideas will help? I working in uncharted territory here. Thanks.

why not run the program with root permissions ??.
like first su to root then give it a su bit ;-P.