Webservice:
http://localhost/Altiris/ASDK.DeploymentSolution/DSTaskManagementService.asmx?op=RunDeploymentSolutionTask
Invoke Command:
<DeploymentItem><ItemType>Resources</ItemType>
<ItemName>PredefinedComputers</ItemName>
<ItemAction>add</ItemAction>
<Item>
<Computers>
<Computer>HOSTNAME,MAC,,,,,,,,,,,,,,,,,HOSTNAME,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,</Computer>
</Computers>
</Item>
</DeploymentItem>
Then use whatever scriptlanguage you like. Powershell, C#, VBScript