I am creating new Octopus Job. Created few required variables (prompt user for some input or selection of static values). But I also need a variable of drop-down type that cannot be populated prior the Octopus Job starts (for example, the version of software to be installed). Please understand that I am not an expert, up to this point created just few Octopus Job and still learning the product.
Scenario:

1. download the latest version of some software
2. save downloaded software to some server at directory that serves as repository for the software (contains all previously downloaded versions along with the latest version)
   When user starts Octopus Job I want to present the user with drop-down selection of all versions from directory (so that user can install the latest or any previous version of the software). So I need a way to populate drop-down list of software versions even before the first step of Octopus Job.
   Is there a way to achieve this?

Tried creating drop-down list with static values and the job works but next time when I download new version of the software to install will need to remember to manually update drop-down list.