I need a JavaScript function (or jQuery plugin) for printf/sprintf. It needs to support named arguments (%(foo)s) and padding (%02d), i.e. the following format string should work:

%(amount)s.%(subunits)02d

It only needs to support s and d, I don't care about all the other format strings (e.g. f, x, etc.). I don't need padding for strings/s, just d, I only need simple padding for d, e.g. %2d, %3d, %04d, etc.