MS-Outlook doubts

I have few doubts in ms-outlook 2003, i use ms-outlook, i am moving out of station for 15 days where i can't access internet. so i am taking my backup of .pst and giving it to my friend and i am giving his email in forwarding mailinglist so that who ever sends me a mail, a copy of that will go to him and he will reply in behalf of me. now my doubts is, i have lot of folders, i manually move few mails to the particular folders, that even my friend knows. now when i come back, i will take my friends outlook.pst backup and import to my outlook. in those 15 days who sends me the mails will be in my outlook also and in his outlook also. he will manually put few mails in particular folder, but in my outlook that mails will be in inbox only, so now when i import his outlook.pst file to my outlook, is my settings becomes as his outlook settings or only my mails will change. i don't want to read again the mails which has read by my friend and replied already on my behalf. when i import .pst of his outlook i will be having those mails in my inbox, but my friend may be moved few mails to particular folders, again it shouldn't show in my inbox. if anyone knows how to do like please let me know. we don't use exchange server

A better way is for him to create a new outlook data file.

Use File.../Data File Management.
Select Add and create a new file with whatever name suits you (or him). You can select any location on your drive for this file, you don't need to use the folder offered.

Now create a new outlook folder in that data file. When he receives one an email for you, he just has to drag it into the new folder. He can also create a folder for the replies he made on your behalf and drag the relevant items from his sent items folder into this folder if that's what you want.

When you get back he just gives you a copy of this file then removes it from his own computer. You add this file to outlook on YOUR computer, then drag the files from the folder into your inbox (and Sent Items if you like), then you can remove the file again.

One note of caution, Outlook sometimes deletes the data file when you "remove" it (I've never managed to work out the circumstances when it does this) so make sure you've finished with it before you remove it.