I need to add a lookup column to an existing list in a sub-site in SharePoint 2007. The data would come from a sibling sub-site. How can I do that? I see the option to add a lookup column, but that only works for lists in the current sub-site. How can I link to another sub-site for the lookup column?
It's not possible to use the column from list across the site boundary from subsite to parent or sibling sites the other way is possible.
is it a custom column or a built-in column OR list based values in a list ( ID , Title) ???
If it's custom then I would recommend to create a site column which is at a site collection level which can be shared across all the lists in the site collection ( includes Subsites)
if it was the other way around then it would have been easier as we can create a lookup site column ( site collection level and share it with subsites)
In your case I guess then we have create a custom column by code which I feel is a overkill :)