NetzaH, what should that custom php script do?

General answer giving that I don't have much information on what you would like to achieve is to try and modify join/profile edit related .php/.html files.

PHP files are located in  ow_system_plugins/base/controllers directory ( join.php and edit.php).

HTML files are located in ow_system_plugin/base/views/controllers/ directory ( join_index.html, edit_index.html).

Thanks Aliia, it's a php script that exports users data to a csv for use in a GIS. Finally i decided to run it through cron to avoid excessive uses with a huge number of users. 

Thanks for you reply, this is valuable information for me also :)

Just use Oxwall Events:

OW::getEventManager()->bind(OW_EventManager::ON_USER_REGISTER, 'yourCustom HandlerFunction');

plus on edit OW_EventManager::ON_USER_EDIT (and OW_EventManager::ON_USER_EDIT_BY_ADMIN if needed) events.

Thats nice, Nickolay, ill give it a try, thanks ! :)

Thanks, Nikolay.