Trigger popup from javascript?

This idea of firing an existing row action popup suits our need too. We have a table of tasks using the standard Task object. We have an existing popup row action with a distinct icon, so it’s easy to identify. We want to override the link on the standard Subject field. But I’m getting an error at the line “skuid.ui.fieldRenderers[field.metadata.displaytype]field.mode”. Is it because Subject is a combobox and the field arguments are different?