Add New Field to calcalendar table

Hi
I am trying to add a new field called "Cost" but am struggling to get this to work.
I have added the field on the chose fields page.
I have tried editing the List page: Before SQL query but I must be doing this in the wrong place. T be honest, I do not understand the query but thought I could apply some logic and add `calcalendar`.`Cost` after `calcalendar`.`Theme` ecah time it appeared. however this has not worked and I get the error...

Error type 256

Error description The used SELECT statements have a different number of columns

URL nexpart.info/calander/calcalendar_list.php?a=return

Error file /home/sites/nexpart.info/public_html/calander/oldinclude/dbconnection.php

Error line 26

SQL query select `calcalendar`.`id`, `calcalendar`.`DateField`, (`calcalendar`.`DateField` + interval `calnumbers`.`n` day) AS `DateField2`, `calcalendar`.`TimeField`, `calcalendar`.`Theme`, `calcalendar`.`Cost`, `calcalendar`.`Description`, `calcalendar`.`Category`, `calcalendar`.`EndTime`, `calcalendar`.`DayEvent`, `calcalendar`.`EndDate`, `calcalendar`.`Period`, `calcalendar`.`Recurrence`, `calcategory`.`Color` from `calcalendar` left join `calcategory` on (`calcalendar`.`Category`=`calcategory`.`id`) left join `calnumbers` on ((to_days((`calcalendar`.`DateField` + interval `calnumbers`.`n` day)) - to_days(`calcalendar`.`EndDate`)) <= 0) where (`calcalendar`.`Recurrence` = 1) and (`calcalendar`.`Period` = 'd') and (1=1) union all select `calcalendar`.`id`, `calcalendar`.`DateField`, (`calcalendar`.`DateField` + interval (`calnumbers`.`n`*7) day) AS `DateField2`, `calcalendar`.`TimeField`, `calcalendar`.`Theme`, `calcalendar`.`Cost`, `calcalendar`.`Description`, `calcalendar`.`Category`, `calcalendar`.`EndTime`,

Can you help?