Greetings,
I have seen your posting here on Freelancer, and I am interested in your project. I am a full-time freelancer with 13 years of experience designing, developing, implementing, and maintaining FileMaker Solutions. The problem that you are experiencing is not an uncommon one. FileMaker XML files are meant for other FileMaker databases, not for other applications such as Adobe's Indesign. However, in FileMaker, the XML can be created neatly and easily, exported as an XML file, and be then imported into Adobe's Indesign for use in your template. Given the cross-platform nature of your application, I would consider this the safest bet as a solution to your problem.
I am prepared at this time to give an estimate for $ 175.00 (USD) for this project with a timeline of 3 days.
Please contact me if you are interested in my services.
Regards,
John Walton