The batch file created probably uses the winnt32.exe to install WinXP. If so, this executable can only be run from a previous version of windows, like Win95, 98 or ME. To run from DOS, you must use the winnt.exe to install it.
Be aware that this version has just about the same options, but the syntax will change. Type Winnt.exe /? to get the proper syntax description. You cannot use this for winnt32.exe. The help file is within windows, it will not function from a DOS booted system.
Another thing, the unattend.txt file must be renamed to winnt.sif when installning from a cd. The syntax is the same, just the filename changes.