Are you wanting to concatenate the values into another object? It isnt quite clear, so here it is.
Concatenating is easier in JS, calculating in FormCalc.
The NumericField3 calculate event simply has:
Whenever either field is changed, it recalculates.
The concatenate button is this:
When clicked a new rawValue is entered in the text field which is made up of the other fields concatenated into one value.
If your rows are fixed you can simply add them up, but if you are dynamically adding rows, you can do this.
Assuming the first data entry row is repeating, in the total field at the bottom add this code.
form1.#subform.Table1.Row2.NumericField1::calculate - (FormCalc, client)
Whenever you create a new row ( i have repeated row1), a new instance will be created before the total row and the new totals will be displayed when the field is edited.