Change status of files from access offline to access online only

I wish to save space on my laptop and effectively shift files that have been stored offline on my laptop to access online only. I have changed the status of folders to online access only but this has not necessarily changed the status of every file within sub or sub-sub-folders, many of whch remain access offline. I simply do not have the time to go through every folder and folder structure - is there not a simple over-write to do this top-down or do I really have to go through each individual file?