California will accept whatever method of service is acceptable in Austria, or you can petition the court for permission to serve the papers by alternative method, i.e. personal service or certified mail.
Once you file the petition and have the summons issued, you will then have a case number XXXXX the case will be assigned to a judge. You have to file a "Motion for Alternative Service". If you need a template, you should contact the family law self-help center (most courts have one) and ask if they have forms for motions. You can use the template for any motion (i.e. if all you can find is a Motion for Contempt, you can follow that format because all motions are basically the same).
Once you file the Motion, you have to request a hearing where you will go before the judge and explain the circumstances and why you need permission for an alternative form of service.
DISCLAIMER: Answers from Experts on JustAnswer are not substitutes for the advice of an attorney. JustAnswer is a public forum and questions and responses are not private or confidential or protected by the attorney-client privilege. The Expert above is not your attorney, and the response above is not legal advice. You should not read this response to propose specific action or address specific circumstances, but only to give you a sense of general principles of law that might affect the situation you describe. Application of these general principles to particular circumstances must be done by a lawyer who has spoken with you in confidence, learned all relevant information, and explored various options. Before acting on these general principles, you should hire a lawyer licensed to practice law in the jurisdiction to which your question pertains.
The responses above are from individual Experts, not JustAnswer. The site and services are provided “as is”. To view the verified credential of an Expert, click on the “Verified” symbol in the Expert’s profile. This site is not for emergency questions which should be directed immediately by telephone or in-person to qualified professionals. Please carefully read the Terms of Service (last updated February 8, 2012).