That's not *all* that helpful--perhaps you forgot to post part of this? But, if I'm guessing correctly as to what you're trying to do, perhaps you should investigate eval. You could specify your format in a single-quoted string (containing a double-quoted string), then eval it.

Perhaps you might also want to look at Text::Template, since it sounds like that might be sort of what you want? I'd recommend this latter approach if it fits w/ what you're trying to do.