速度的にはどうなんだろ
on replaceReg(str, fnd, opt, rep)
set JsScr to "
var str = " & quoted form of str & ";
var fnd = new RegExp(" & quoted form of fnd & "," & quoted form of opt & ");
var rep = " & quoted form of rep & ";
str.replace(fnd, rep);
"
set ret to run script JsScr in "Javascript"
return ret
end replaceReg