Is there a way to specify a specific Portal Row in a calculation in a way that is similar to specifying a specific repetition in a Repeating Field?

For instance, if it were a repeating field and I wanted the 4th repetition, I would write "Field1[4]".

If I want the data from Field1 in the fourth portal row, how would I do that?

The actual context for this is that I am working with a very idiosyncratic website and I have to transform a lot of PDF files that have a lot of tables into web pages. (The reasons for doing such a dumb thing are too complicated to go into.) I have to have the normal content in plain text, but the tables have to be transformed into HTML. at this point I have the tables transformed into related files that show up very nicely in portals. I have a script that will transform them into HTML, but I keep thinking that I should be able to create a Custom Function that will do the same job better. But I can't see how to do it if I can't make the calculation iterate through the portal rows.

The FileMaker function which makes this possible is GetNthRecord ( field, record number ). You can use the portal's relationship, then a field.

To iterate thru the records in a portal there is a Custom Function, GetRows, by Bruce Robertson, at:

http://www.briandunning.com/cf/309

also requires

http://www.briandunning.com/cf/308

He has another similar one, for named objects: GetRowsObjectList( ObjectList; N; delim1; delim2 )

All (and many more) at:

http://www.briandunning.com/filemaker-custom-functions/list.php