What kind of access do you have to this webspace? Do you have an ftp account or
do you have to go to some upload-site to put your stuff there?
If you have ftp-access it is possible to upload using dreamweaver, if you don't, then there is no way (that I know of) to use dreamweaver for the uploading.
There is probably an admin-site that you can log on to. On this site it should be possible to modify the content of you site.
Some more questions that could help to solve the problem:
Do you have a 'free' account somewhere? (If so, then you probably don't have ftp-access, thus making it 'harder' to upload your stuff)
What is the address? (If I know this I could possible give you a way to upload you stuff)
Do you have a lot of different files to upload?(If so then I hope you have ftp-acccess)
If I'm more awake tomorrow I could be of more use, I think, am a bit sleepy now....