>perl -wMstrict -le
"my $s = 'abc 123 def 45678 g 90 h';
 print qq{'$s'};
 ;;
 $s =~ s{ [^\P{PosixDigit}257] }{-}xmsg;
 print qq{'$s'};
"
'abc 123 def 45678 g 90 h'
'abc -2- def -5-7- g -- h'