OpenOffice Base link to dbase files on different assigned drives?

I am attempting to run OpenOffice portable base on a usb stick with a link to a dbase file. I can set it all up as I wish, but I use the same USB stick at work on a variety of machine with a number of networked drives. Sometimes the drive letter is assigned differently, then I get an error message, how can I get OpenOffice base to always read a 'local' version of the dbase file?