# wrap the initial declaration in a begin block
BEGIN { $softwarepath = "/usr/local/etc/software"; }
use module;

# or eval the use, so it happens at run time
$softwarepath = "/usr/local/etc/software";
eval { use module; }

# or do the require/import yourself
$softwarepath = "/usr/local/etc/software";
require module;
module->import();

# or modify the module to accept the path as an option
use module path => "/usr/local/etc/software";