I need to be able to pick up the content of a specific portal row into a calculation - sort of using the portals as variables arrays.

I would like something like this:

calcfield is made equal to:

GetportalContent(relationship,portal_row_number,related_field_name)

Does a function exist to do this?

Couple of ideas:

Just add the calc field to the related file -- it'll calculate for what amounts to each portal row, but it'll certainly calculate for the row(s) you want to see.

or...

Use a separate relationship to define the parameters for which portal row you want to extract information from. Create a calc field that returns the info from this relationship. Put that field somewhere outside the portal ('cause it's from a different relationship).

Hope (at least) one of these ideas helps.