It is possible create folders in Multisites?

I have a domain .. with many posts that links to images in https://www.domain.com/pics/

I have many similar domains, and have decided to consolidate it into one mega multisite to help with the upgrades etc. So, I have created a new multisite with subfolders, and added a new site say https://www.multisite.com/olddomain

Then I have installed the WordPress MU Domain Mapping plugin, set up everything so now the https://www.multisite.com/olddomain/ works as the old https://www.domain.com

Prior to parking the domain and mapping, I exported all posts and images and everything and imported everything into the new installation. I suppose that has everything that is needed in the posts, although I haven’t checked. I did note that there was no import of my media library and all a lot of broken links, all because I often was linking repetitively to images in my /pics/ folder.

Q) How do I create a new https://www.domain.com/pics/ folder on the multisite (site id=11) so I can just ftp all the old images into the folder? Is there a way?

Thanks in advance
HART -aka petLvr