How can be correct the error in the following program segments?

$//$ assign array element $2($the value $3)$ to number

number $={?}^{**}zPtr[2]$;

a$.]$ to $]$

b$.{?}^{**}zPtr[2]$ to ${?}^{**}zPtr[3]$

c$.]$ to $zPtr[1]$

d$.]$ to $zPtr[2]$

e$.{?}^{**}zPtr[2]$ to ${?}^{**}zPtr[1]$