ioBanana has already a SITE RANK ftp command and a !rank irc command.
Code:
SITE RANK <type> <username> [sections <sections#>]
SITE RANK <type> =<group> [sections <sections#>]
SITE RANK <type> #<x> [sections <sections#>]
<type>: AllUp, Alldn, MonthUp, MonthDn, WkUp, WkDn, DayUp, DayDn
sections: space-separated sections numbers to include or exclude (0-9)
sections definition MUST end with either !* or *
sections examples: "!0 !2 *" or "0 1 2 3 !*"