Use FvwmM4 module to avoid creating env vars. Use -m4-prefix -m4-prefix-defines options to avoid name conflict and prevent from substitution of built-in defines (like FVWM_USERDIR).

OPTIONS=color,hilite_pet,news
OPTIONS=number_pad
OPTIONS=!autopickup

OPTIONS=name:gavenkoa
OPTIONS=catname:Catty
OPTIONS=dogname:Doggy
OPTIONS=horsename:Loshadka