How do I extract a value from a wave and save it as a variable?

Hi,

This may be a very silly and easy to answer question, but I have been hitting my head against the wall trying to find the solution on my own and getting nowhere. Is there a command that will allow me to extract a single value from a preset wave and assign it to a new variable? Something akin this:

variable r = extract[wave1, row1]

I know the extract command doesn't work like this, but something to that effect.

Thanks,