Hi, need a script step(s) to paste the contents of the clipboard to the next unused row in a portal.

Which, I suppose, is by definition also creating a new record in the related table.

In this case, my portal contains only one field. Both the portal and the field are from the same table.

But as long as we're on the subject, I'd also know how to do the same thing if I were to have to specify a particular field because the portal contained more than one field.

TIA!

I'm not sure where the data is coming from, but you usually want to use the "Set Field" step instead of "Paste". Either way, this is how you create a record via a portal (with "allow creation of related records" enabled on the relationship):

1. Make the portal, or a field/object in the portal active. This can be done many ways, but I often use a "go to field" step.
   
2. Go to last portal row
   
3. Set the contents of your field, and if the relationship was setup properly, a related record will be created
   

Perfect, thanks! It works with "Paste" too.

I'm not sure where the data is coming from

The data comes from the operator manually having selected and copied a text string from someplace, such as from within a text field or some other document.