some question on using VBA?

hi, thanks to all, but I have some question on using VBA.
I want to know if the word have the feature below:
1. Is VBA support operate xml, like in .net?
2. Can I use application write some VBA code to the word? I have write some
VBA that store in a separate word, and upload it to a web site as template,
when user download other document, I want write the VBA code to the new
document.
3. Can VBA visit file system? When I edit a word, then I want to click a
button to upload current word to the web site. I will copy it, and the
upload new document to the web site.