Extract a specific text with DAX or in Custom Column in PowerQuery (vehicule registration number)

medmbchr1989 

you can try this in PQ

= Table.AddColumn(#"Changed Type", "Custom", each
[a=Text.Remove([Column1],{"-"," "}),
b=Text.PositionOfAny(a,{"0".."9"},2),
c=Text.Middle(a,List.Min(b),List.Max(b)+1),
d=Text.PositionOfAny(c,{"a".."z","A".."Z"}),
e=try Text.Insert(Text.Insert(c,d,"-"),d+2,"-") otherwise null
][e])

pls see the attachment below

Easy enough,

= Table.AddColumn(#"Changed Type", "SN", each let start = Text.PositionOfAny([Text], {"0".."9"}, 0), end = Text.PositionOfAny([Text], {"0".."9"}, 1) in try Text.Replace(Text.Range([Text],start,end-start+1), " ", "-") otherwise "")