I want to extract a cell reference from a formula in a cell

I tried the right function referenceing the cell but it returns the right
portion of the function result

how do I specify it to extract the physical formula text in the cell and not
the formula value in the cell?

example... a cell b5 contains the formula "='Execute Dealer Plan'!$P647"
which has a value of "select status"
if cell b6 contains formula "=right(b5,4) I'm wanting "P647" returned and
not "atus"



--
Jim