Read/write to XML file in data folder

[arek1]

Hi All,

I know this forum is not for learning PHP programming but I need help about specific GS PHP<=>XML connection.
Generally I looking for solution how to write data from form into XML files in data folder.
Next step I will looking how to read this data.

All I need is simple instruction like have in Joomla documentation here:
http://docs.joomla.org/Accessing_the_dat..._JDatabase

Just few lines of code how to write/read data in Get-Simple CMS.
Can anybody spend some time just to point me where to start. It is easy find information how read/write in SQL but not in XML way how it is in GS CMS.

Thank you in advance.
ArekS