When you say a "batch file", there are at least two possibilities.

One is you use the Scheduled Job feature of W2K. In there you can set the ID under which it runs and so provide a domain ID with suitable permissions. A simple way to determine if you have it right is log in under the ID you plan to use and run it manually. This has nothing to do with SQL.

The second option is using SQL Agent to run it. Here the job step runs under the ID that SQL Agent is set up to run under. Changing that ID may give you correct permissions however it affects all SQL Agent jobs at once, so care must be taken in making the right choice as this may either break other things or open up security issues.

There are possibly other alternatives as well.