Substring of Url's on a column in Sql Server 2012 -

since new sql server, trying take substring of url in item url column eg: http://mysite.comp.com/sites/myactions/related party action

i want related party action url. have tried charindex , substring,but confused positioning. want every url in itemurl column this.please me select query.

i got answer.......

select substring(item_url, charindex('myaction/', item_url) +9,len(item_url)) [website] latest_audit_dump