I've never hit this milestone so a bit of guesswork on my part, but some of my thoughts:

1) Plenty of non-scholars have made it to school leadership

2) You will need to have a high CEP, probably serving as HOD but high-performing and handling cross-department/full-school affairs

3) MOE HR identifies certain of these people for a VP interview. Not everyone clears this.

4) If you're really interested, talk to your RO about this and how you could work towards moving up the leadership track (assuming you're a current HOD) - can couch it as further down the road, if you think it's not likely to be so soon. If you feel too embarrassed to do even that, it might also be a sign about your readiness for this?