Is there any way to set the value of a Perl Constant to a value in a Perl Hash?

This is not working:

```
use constant TEST => $configData{'key'};
print TEST."\n";

```

This prints just the newline character.

Is this a misuse of the concept of a Constant? The values are still known at compile time, they just do not live inside a perl module or the perl script itself.