Thanks. I agree that most of your comments don't really apply to this particular application. What little exposure to formal Computer Science methodology was in Structured Programming, but I have trouble convincing myself to write subroutines that will only be used once in a specific order. :-)

(Though I'm sure there is some room for increased modularity. Any specific suggestions?)

You're absolutely right that I should have used an expression rather than a block in my 'map' statement, and I would never have thought of constructing my list using the 'x' operator (though I had originally tried to use it to construct the $placeholders string). I will definitely incorporate that change.

Impossible Robot