I quickly looked at the prohosting site but couldn't see if they offer it ...
telnet or secure telnet (ssh) makes it possible to login into your server and do much more things easily than you can do with ftp ...
basicly what you could do is open a dosbox (if on Win) and type telnet
www.yourdomain.com If it asks for a username and password it's activated ... (that doesn't mean it's activated for you ...)
SSH (which is more secure) works with an encryption level and needs a little bit custom setup first ... (which IP's are allowed etcetera) but the principal is the same. (you can use putty for both telnet and SSH or any other little nifty uttility)
So when you have access to your server with SSH/telnet and you are logged in you are in your home directory which is the root directory of your website ... (classic setup) ...
be carefull ...
making typos can be lethal if you have no good backup ... (and don't ask your provider to restore your home directory after you deleted everything because he is NOT gonna do that ...
first things first ...
type pwd
it returns /home/yourname
second type man pwd
now you get the help files of the command pwd ...
handy ... ;-)
to exit ... keep on entering or CTRL+C
second a few commands that come in handy ...
ls -ltr list all the files with last used last
vi text editor on linux/unix
to exit vi :q! exit without saving ...
better read the VI help pages first ...
In your case you would use the cp command and later on a rm to dlete the old ones
cp -p /home/yourname/A/* /home/yourname/B/*
would copy everything from dir to the other and keep the file permissions ...
afterwards if you checked it do a rm (remove) and your done ...
BUT .... please be carefull ... you don't have a trashbin like on windows ... deleted is deleted ...
Have Fun ...
Greetz
Knuff