How to hack an improval of recurring events

[thegve]

I'm planning to use the plans calendar in an administration system I'm writing for a foundation that helps parents with hyperactive children in spending a sum of money they get from the government for care.
As you may understand a lot of recurring events wil occur, and occuring events can change. In the system that plans uses, if I create a recurring event, it copies one event X times til the end time.
I want to be able to "feed" plans some XML I create from my PHP based system.

Can I hack plans in such a way that it uses multiple XML sources, or that it reads from my XML source, and writes in its own. I can read in the plans XML and include that in the XML my script outputs.

I hope you can understand what I'm saying , if not, I'll try to make myself more clear but I think you can get the point. Thanks in advance for the nice product and your help.

edit:

I Have desided to write my own calendar system anyway, as Plans doesn't fit my needs in a couple of ways. So no help is needed anymore.