SETVALUE using Perl hash

I am looking to assign a weight to respondents from particular zip codes for my study. I am trying to use a perl hash to lookup the weight value needed and save it in the free format variable I have called "ZipAdjustment_weight" - actual zips are captured in the value S25. I need to save as a variable in the study to do a calculation with a later response.

Similar to question asked here, and I got this to work to return the value:

https://legacy.sawtoothsoftware.com/forum/30866/look-up-value-based-on-zip-code?show=30866

I just can't get this value to be stored in a variable - Thoughts?

[%Begin Unverified Perl
my $zipCodeQuestion = 'S25';
my %zipCodes = (
	12345 => 0.88,
	12344 => 0.97,
	12356 => 0.97,
	12332 => 0.88
);
SETVALUE("ZipAdjustment_weight", $zipCodes{GETVALUE($zipCodeQuestion)};
End Unverified%]