On gma3 (within the commandline), the asterisks (*) always represents a wildcard character.
Use the percentage-sign (%) instead, to indicate a scaling value.
e.g. (Assuming Physical readout is chosen)
Attribute "Pan" At % -100
would be the gma3 equivalent to the gma2 syntax
Attribute "Pan" At * -1
thanks Andreas !
the syntax work perfectly !