@Castagnet judicael,Thanks for posting Q&A.
From your description, I know that you want to set custom password expiration time when using Windows LAPS.
Based on my researching, I find that you can custom password expiration time in Intune. You can configure Password Age Days in Endpoint security > Account protection > Windows 10 and later as Platform, Local admin password solution (Windows LAPS) as Profile > Configuration settings.


Hope above information can be helpful.
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