When dialing in how can I force Windows XP to use offline files?

Hi

I have a customer who when dials in would like to send and recieve emails so
he needs to be online and connected yet he would like to work offline on his
shared drive folders and files.

The reason for this is that when he dials in and accesses files from the
shared drive it is to slow over the network would just like to work with his
offline files which were syncronised when he logged off.

Any Ideas??

Many Thanks

J