assign variable to a date cell (excel)

[timepro timesheet]

hi:

my app is in xhb+wvw+ps32+dbf

1. date field in excel cell (this excel file should be open only for reading.)
cdest=diskname()+':\tax\einvoice\creditnote\'+creditnotefilename+'xlsx'
oexcel=createobject('excel.application')
oexcel:workbooks:open(cdest)
osheet=oexcel:activesheet
xcelRows:=osheet:UsedRange:Rows:Count()
for exxx=2 to xcelrows
*
EINVDATE:=osheet:cells(exxx,7):value
-type(einvdate) returns 'C', inspite of being a date cell*
-so i have to code this: if type('einvdate')='C';einvdate=ctod(einvdate);end
*
next
oexcel:quit() & AFTER QUIT, STILL PRESENT IN TASKMANAGER
oExcel = NIL
release oExcel

2. if 'oexcel:activeworkbook:saveas(xlsname)' saves the open excel file.
what is the command (from within the app) to 'not save' any changes made and close the file.

3.how to edit/write on a protected cell from within my app.

4.how to find if an excel file is 'already' open by another-user/you.

thank you