Put machine in specific OU automatcially

I have a script that runs post ghost build that accepts hostname. This then updates the unattend.xml with hostname. Works great.

I now need a way for the tech to enter the OU the machine account will be placed in, so the builder doesn't have to manually go into AD and move machine account from default OU. thought this would be something DS woudl have but doesn't look like it (please dont suggest using 'apply system configuration' - thats just another manual task.

any help appreciated!