Conversion of false N+E to latlon

Hello GRASSERS,
  
    I'm trying to find the method necesssary to convert false EASTINGS or false NORTHINGS
  to actual Lat-Lon values. I have some data of the conterminous USA in false (NE) values and
  would like to convert various site data into that projection (Lambert CC).
  Any help would be greatly appreciated. Anyone working in GRASS Lambert CC?

  Thanx,

  Doug Bradley
  Southwest GIS Support Center
  Albuquerque, NM
  (505) 766-8400