R help - Nov 2008 - R system on USB: how to enter relative R environment path in Eclipse/StatET?

Hi,

I am trying to set up a portable R environment and wanted to use Eclipse and
StatET as the editor. But when setting the R environment in StatET I cannot
figure out how to enter a relative path. Has anybody succeeded in doing this?
(eclipse and R are both in the common directory \programs on the usb key)

Many thanks for any hints,
  Werner