Basic DataGrid question

[Paul Gabel]

Hello List:

Today I'm trying datagrids for the first time. I'm collecting data in  
a field "Collector" with a dozen or so lines, and four columns set  
using: "set the tabStops of field "Collector" to 100,100," etc. Then,  
after many lines of data have been collected, I use:

put fld "Collector" into pText
set the dgText [ pFirstLineContainsHeaders ] of group "Final Display"  
to pText

Final Display is the datagrid.

This works great! But, before I put the field into the datagrid I need  
to do an operation on the third "item" in each line and put the result  
into the fourth "item" in each line. An "item," of course, is not an  
item. It's text in a column (I have vGrid set to true). But I can't  
figure out how to access it. I've tried various delimiters, but  
nothing works. I can't just say: Get the number in column 3, operate  
on it, then put the result in column 4.

I'm trying to avoid using arrays (because they confuse me).

Any ideas? Thanks.

Paul Gabel