Backup documents on server but not locate them there

I know my question title is confusing but its kind a hard one to describe, but should be easy.

Il keep this fast and simple.
Running server 2003 exchange 2003 on a domain. For our desktops there documents are actual located on the server (We change the location of My Documents on the machines)

For our laptops we do the same thing but you have to use Offline files/Syncing. This causes problems sometimes when they leave the building. What I would like to do is reverse this for the laptops, having the server pull the documents from the laptops when connected into our network. This would ensure they always have access to there files.. but now the problem is in reverse.. the backup might not always be complete. Is there any way by policy or local setting to constantly update the server side with there documents without the use of 3rd party software. We are not against 3rd party but that requires approval and installation and ect ect.. you get my drift.