How open the lead record From Ribbon Button"NextLead"

i have a ribbon button "NextLead" on Homepage grid.
i want to perform action as when click it Open the nextSchelduled Lead and similarly opne other nextLead.
A "ScheduledDateTime" Attribute Is on the lead Form and "NextLead" Ribbon Button Should check the ScheduledDateTime Attribute and open the record and when close it it open automatically nextLead and so on...

Note: I have a webresource javascript on ribbon button action and know how open Existing record but in my case how Can check Attribute While Lead form is not Open
on the Main HomePage grid

Muhammad Sohail