Source of USE command or DBUSEAREA function

[MarcoBoschi]

Hi to all,
Is it possible to have source code of Use command or dbusearea function?
I use this Harbour.exe

C:\xharbour\bin>harbour
xHarbour Compiler build 1.2.1 (SimpLex) (Rev. 6634)
Copyright 1999-2009, http://www.xharbour.org http://www.harbour-project.org/


Thanks in advance
Marco