Modern States voucher question

[magflo]

I know this is going to seem like a strange question, but has anyone redeemed their MS voucher to use for a different test than the one they earned it for?  Reason I ask is because I had my son scheduled to take the DSST in Info Systems before the end of September's free retake promo so that if he didn't pass it he would get a free 2nd chance.  But then I decided to have him try the Modern States course for CLEP Info Systems and he finished the course and just received his first MS voucher, yay!  Problem is, it seems the CLEP Info Systems is more difficult than the DSST Info Systems exam. I'm wondering if I should go ahead and pay for him to take the DSST in Info Systems as originally planned and use the MS voucher for another test I was planning for him (CLEP Marketing or Sociology).  Is this allowed? Since this is our first MS voucher I've yet to go through the redemption process but I imagine it's just entering the voucher code on the CLEP website when purchasing your exam but does MS track vouchers to the exams?