Windows 2000 doesn't allow a backround task to instantly steal focus. Two REG_DWORD values control the process. Use Regedt32 to navigate to:
ForegroundLockTimeout defaults to 200000 milliseconds. It specifies that time period, after user input, during which the system will NOT allow an application to force itself into the foreground.
ForegroundFlashCount is the number of flashes the system will use to notify you that a backround tasks wants focus. If ForegroundLockTimeout has elapesed since the last user input, the window will automatically be brought to the foreground.
NOTE I suggest that you select the Decimal radix when viewing or entering data in these value names.