Backup and restore

I saw the thread fro previous.. but no enswers posted.
Moodle claims, rightly, that xml support doesn't appear to be compiled into PHP. Checking phpinfo(), there isn't an xml table to even say enabled or disabled.
PHP Version 4.2.3

Is there a way I can get it to work without having to recompile php and without having access to php.ini (on linux system).

I can't do backups (obviously) and this makes a few other things hard.

I can't say I nderstand why xml is the only option for creating backups, but hey, I know it should be a standard part of PHP now, so I need to work around it somehow.

thanks.