in reply to defining a new var on the spot

Can I define a new variable with a name that stored in another variable?
I always read this as "Can I poke myself in the eye with a sharp stick?". Yes, you can.

If the answer is "define a new variable with a name defined by another variable", you've asked the wrong question. Back up a step. What's the problem you're really solving?

-- Randal L. Schwartz, Perl hacker