SQL & PL/SQL

i have a program that will create and drop a directory. this is my code

i no you can create a direcotry like this

create or replace directory Signature as '/sig/images/oo1'; this works fine

now i want to do this in the code

declare a variable
strDir as Varchar2(100);

strDir :='/sig/images/oo1' ;

create or replace directory Signature as strDir
is this possible