Installing Symantec Enterprise Vault OWA extensions

Hi All,

I am planning to install OWA extensions on my Exchange 2010 CAS server in order that users can access Archived mails using OWA.
I was able to plan almost everything i.e

Installing OWA extensions on 2010 CAS box
Creating the ExchangeServer.txt on EV server.
Modifying the Desktop Policy.

But i have an confusion while going througt this Article
http://www.symantec.com/business/support/index?page=content&id=HOWTO38207#v9666766

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To configure the Data Access account for OWA

1. Create or select a domain account to be used for anonymous connections to the Enterprise Vault server. This is the Data Access account. The account should be a basic domain account; a local machine account cannot be used. The account should not belong to any administrator group, such as Administrators or Account Operators.

   If you are configuring both Enterprise Vault OWA Extensions and Domino Mailbox Archiving, it is important to use the same account as the Data Access account for both features. If you have already set up Domino Mailbox Archiving, note the details of the account specified on the Data Access Account tab of Directory properties in the Administration Console

Which says to configure the Data Access account.
Is it actually required in my case where i only have Exchange mailbox archiving and no domino mailbox's??

and also do i need to run cscript owauser.wsf /domain:domain /user:username command.

or simply doing above 3 steps should help me get users access to archived emails using OWA