Hi Lance, 

Just to clarify, are you trying to configure WebLink to display columns dynamically based on custom search forms? If so, there isn’t a way to configure this by URL. However, if the results of your custom search reside in specific folders, as an alternative solution you can set up WebLink to display unique column views for each of those folders. You can follow the instructions detailed in this Answers post to help you get started. 

If the search results reside in various folders and you’re looking to filter the results using field values, another option would be to add Sort Selector to your Search Forms. The Sort Selector will add a drop-down list to your custom search, which will enable you to sort search results based on templates and fields. For more information, feel free to check out this page in the help files.
  
Let us know if any of these options work for you. Thanks!