Not sure which forum to put this is as it cover every section!

I am running a competition on my website which will collect me email address's for a mailing list.

I want a form which will do this for me. I am ok with a simple HTML form but have a few questions to see if I can get it to do exactly what I want

Preferably without using PHP (As I havent read about it yet) although I'm 90% sure this wont be possible (especialy my last point)

Questions below:

1. My mailing list will be in excel, can i export directly to this format (CSV or xlsm)?
2. I will have a drop down list which will have around 720 values! This is far too many so I wondered if I could cut this down by another part of the form

IE: If x is selected, then the drop down list = abcdef. If Y is selected then the drop down list = GHIJKL.

3. Now this is the tricky part! My website is built in HTML but I use wordpress for my forum and blog. Can I make it so my form registers the 'form user' for my wordpress account?

Any help would be greatly appreciated as I'm looking to go live at the beginning of Dec