Hi!
(...this seems to be a z/OS problem, version not known and my knowledge is from version 7)
I'm afraid, DSNTIAUL is extremely simple program. There are only one parameter to be given in SYSIN file (SQL or none) and it does not have direct effect on format.
But as you can use SQL, you may try to format that varchar-field to char, right?
Also some people have been using a post-processor (an extra step/program, that manipulate file afterwards - no SQL are needeed).
Cheers, Bill