You do not ask for the Subpoena in court. You have a subpoena issued with a request to the work. If you have an attorney, they can help you with this. If you do not have an attorney, you will have to have your subpoena issued by the court clerk. The proper form is Subp-010.
Issuing subpoenas can become fraught with technical issues such as time limits, notifying multiple persons (e.g. if you want to subpoena employee records, you need to notice the employee before the subpoena is served), etc. If you believe it will make a meaningful difference in the support, you should consult with an attorney to ensure everything is done correctly.
This answer is provided for general informational purposes only and is not offered as and should not be treated as legal advice. This answer also does not create any attorney-client relationship. Every situation is different and you are urged to consult with an attorney.