If you specify what you mean by "dynamic," this'll be easier to answer, but generally speaking Velocity can be used to craft whatever links you want.
Thanks for your reply. For example a lead already visited a page on our site and did an action. This page and the action is shown as a custom object. We want to show that lead a facebook share button that populates the page in the lead's custom object.
Hope that clarifies a little.
So build the link using the property of the Custom Object. Can't offer more without real-world example of your CO in the Velocity context (SomethingList[idx].someProperty).
A lead has field in the custom object that has a field name labeled url ie: ( jamessmith-876794 ). I would need to add the domain (youcaring.com) to the field name by velocity scripting and then that is what we would want people to share on Facebook (https://www.youcaring.com/jamessmith-876794 ).
I'm also not quite sure how that program token would even fit into the feed dialog?