Clone site to multisite network

Hi,

Because my webhosting service doesn’t allow WordPress wildcards, I had to make subdomain like this:
– make a map in the ftp root
– copy wordpress files to that map
– edit wp-config
– install wordpress
But now, I’ll change to another host very soon (a host which does allow WordPress Wildcards). So I’ll setup a multisite network.
But my question is, how can I make a copy of my subdomains and import them to my multisite.
I can’t just move the files via FTP because when you make a site via multisite, a FTP folder isn’t created.

Many thanks in advance!

Thibault