Where a report is named “Headcount”, is of the type Summaries, and you want the file to be created in the root R: directory the paramter would be:
rpro9reports.exe /u:sysadmin /p:sysadmin /rpt:”Headcount” /pgp:Summary /pgs:pdf /el:R:
(NOTE: It appears that reports with a special character in the name (exclamation point, for example) return an ‘invalid report name’ error.)