U can create a service in windows NT by following command and this would avoid 
batch file
dsmcutil install /name:"Adsm Scheduler" /clientdir:"c:\program 
files\ibm\adsm\baclient" /optfile:"c:\program files\ibm\adsm\baclient\dsm.opt" 
/eventlogging:yes /autostart:yes /commethod:tcpip

U should run this command from baclient directory.
Also if u want to backup only directory then u would need to exclude everything 
else and u need to specify that in dsm.opt
I think this will solve your problem
thx
razdan