AppleScript: coerce – coercion of measurement units/values in quarkxpress

(*
qxp_coerce_01.applescript

Coerce the swiss army knife to convert measurement units.
*)

tell application "QuarkXPress Passport"
    tell document 1
        -- get bounds of generic box 1 of document 1.
        set {t, l, b, r} to bounds of generic box 1 as list

        -- for example t (top of bounds) would be coerced from
        -- vertical measurement ('FXVM') of QuarkXPress to a real number
        -- "8,467 mm" => 8.466644287109
        set t_as_real to coerce t to real

        -- for example l (left of bounds) would be coerced from
        -- horizontal measurement ('FXHM') of QuarkXPress to a string
        -- "20,461Â mm" => "20,461Â mm"
        set l_as_string to coerce l to string

    end tell
end tell