Not sure what you mean. I am using the following code..

oExcel = CREATEOBJECT("Excel.Application")
oExcel.Visible = .T.
oBook = oExcel.Workbooks.FOPEN(xlFile)
oSheet = oBook.ActiveSheet

and it will allow me to open it and write to it even though it is ReadOnly. I want to prevent this from opening until someone else is done using it.