Scheduled Tasks - Webservice

1) I have quality assurance application (http://www.myweb.com/QA)
It uses form authentication

2) I do have a webservice. It uses Soap header as authentication. I have create a subfolder in my application (QA/WS2) and upload there Service1.asmx file.
I haven't created any web.config file for webservice.
Also I have uploaded dll and pdb for webservice into QA/bin folder.

3) I wanted to schedule webservice as Scheduled Task. It does return 200-OK code, but I believe it never starts (it should simply insert one row into database table, but it doesnt happen).

My questions are the following:
1) Can I use Soap header authentication for Scheduled tasks?

2) How to configure webservice to be run as Scheduled Task - do I need its own web.config file in WS2 folder, or any other? I do not know anything about configuration.

3) If it doesn't work - what format should be used for Scheduled task (I am using form authetnication for my website)