PCD.xls file is written by a reporting system on rcpepicor. It is managed via website link. PCD.xls file is under p21 reports.
http://rcpepicor/reports/pages/folder.aspx
To edit a report open the link above in IE and find the report. click the report drop down menu arrow on right side and then manage. This only works in IE 11 (at least as far as I have seen). Permission to edit is based on AD login in windows so it has to be done from domain admin account.