Hello, I've worked with software to communicate with financial institutions in the USA, specifically ACH transactions. Please have a look at the resume in my profile regarding my experience with banking software while at IPS Of Boston.
The clieop03 format is similar to the ACH format. Creating a PHP class to add the other information, and convert it to the 20022 XML format should be fairly straight forward.
Regards,
John H. Ward, Jr.