Get familiar with MDT UDI which provides nice user friendly interface during Wipe and Load installation, where you can select country (as example), it will write new variable based on what you could active step in TS to move computer account to specific OU. MDT integration might sound heavy at the start, but I simply loved UDI for its design pages. Alternatively, you could seek a powershell script or custom 3rd party hta to do the job.
https://www.anoopcnair.com/customizing-udi-wizard-with-udi-designer-using-sccm-configmgr/