$String = "François-Demaison!?!#@$%^&*()_+\|}{○<>??/ €$¥£¢ \^$.|?*+()[{ 0123456789"
$String -replace '[^\p{L}\p{Nd}/(/_/_]', '_'
In Powershell
$String = "François-Demaison!?!#@$%^&*()_+\|}{○<>??/ €$¥£¢ \^$.|?*+()[{ 0123456789"
$String -replace '[^\p{L}\p{Nd}/(/_/_]', '_'