Powerscript to C#

The attached file is a sample script that will login to a site then using
and index file , which is simple delimited text,  it  retrieves
pdf's.
Would greatly appreciate it if someone knows the C# or vb.net equivalent
code for these parts:   post the  username and password, get the  cookie, and then
request the PDF's , using a URL  that's in the index.
Looks to me that the  request for this has to include the  cookie in the
header, otherwise it just gets redirected to the login page.

Reason I don't want to just use the script is that I need to be able to load the index into a
DB and filter out only the ones we want. Sure, I could rewrite the index file, but
a  .net version would be very handy to have.

So, this part
"the C# or vb.net equivalent
code that will post the login creds, get the  cookie, and then
request the PDF's , using a URL  "


Thanks