[GRASS-windows] No such file or directory

[Peter Brooks]

Hi, I've downloaded the 'ncexternal' data from the grassbook website -
  I created a 'ncexternal' mapset folder and copied the files into 
there.

Whenever I try the examples that access import or process these files 
I get an error message in GRASS. For example on p62

r.in.poly in=newfacility.txt out=new_facility_1m

gives

newfacility.txt: No such file or directory

although the file is there. I have tried adding the folder to the 
Windows path, but that doesn't solve it.

I am probably doing something stupid or have missed (or skipped :) 
something obvious... I would be grateful for any help.

Many thanks
Peter