gMode = 1 && global mode variable (public)
try
  oFrm = createobject('frm')
  oFrm.SomeProcess()
catch to loExc
finally
endtry

define class frm as form
  proc someprocess()
    error 1
  endproc
  proc error(nError, cMethod, nLine)
    if gMode = 1
      * I want to throw the error here. Is it possible?
      * error nError && does not do it because the err.lineno, err.proc will be changed.
    else
      do errhand with nError, cMethod, nLine
    endif
  endproc
enddefine