Be sure you understand the difference between a runtime variable and a
compiler variable, Bob. On the home screen, there's a link for "Learning
Setupbuilder." You might read the "Names-Variables" section there.
Your runtime variable is not evaluated until the end-user runs your
installer.
One possibility would be to wrap the code in your screenshot inside a
#iffile block.
"The #iffile conditional-directive determines if a particular file or
directory does or does not exist on the development computer. You can use
the conditional-directive to mark the beginning of the block of code that
will only be compiled conditionally."
jf