Copy rows from multiple workbooks into a master one

[intercooler]

Hey guys,
Any ideas on the following:
I have multiple people on various locations filling in similar to the attached file on a daily basis and saves it on a shared drive,
What i need to do is copy all data from each file into a master one and have it updated automatically so i can pivot it.
With each new day, the salesmen contonue to fill in their files by entering new rows. And i would like just the new rows added to the master file. Basically i need a combined spreadsheet with all current salesmen data. I have a macro that enters a fixed modified date in dd/hh/mm, and i would like to copy new rows based on it. Any possibility that this is done by VBA and in a way that the files should not be opened at the same time?
Shared worksheet would not work as the data is sensitive and one salesman should not be able to see the oher salesmen's sheet.

Hope i made it clear enough.

Regards and would appreciate any ideas