Working on many excel files - problem with cells update

Hello everyone,

I've got a little problem while working with many Excel files at once.

I've build a folder structure as in zip attachment, and the main problem is all forumlas in C column in Example File (located in example folder 2) are working only when my source files are open. Is there any possibility to let Excel get information from source files without actually opening them? For now there is not a big hassle because I have very few files but i want to have it all automated since begining.

Thanks in advance!