# define a variable containing a single space

blank :=

space := $(blank) $(blank)

# split string $3 with $1 as separator and return the token in position $2

define token

$(word $2, $(subst $1, ,$3))

endef

# split string $3 with $1 as separator and reassemble it using the indexes in $2

define reorder

$(subst $(space),$1,$(foreach i,$2,$(call token,$1,$i,$3)))

endef