Need help with simple vB mod

[Vertexxx]

I am very new to vB and need to mod vB so whenever a change is made to a vB user it will make a simple DB entry so I know that I need to re-sync that profile with my site's user profile system.

For instance lets say a user changed their password in vB. I need to then update a DB entry from 0 to 1 so a cron that runs every few minutes knows to re-sync data for that user. I am hoping there is one place I can put one simple mysql update to update whenever a user or admin changes a profile.

I don't really know where to start on this. Also I am trying to minimize custome code in vB as much as possible so it keeps working correctly with future version (that is a headache I don't want).

Hmmm it appears nobody knows how to do this... Well I have narrowed down where to put the update php/sql code (class_dm_user.php) but I am having trouble finding the variable that stores the user id.