No useful script. Just an little lesion.
Loop virtually through only the selected lines in file.
The cursor will not move!
We access each line by its number only.

– – –

Best to learn is to do some lessons.
So i will show my steps creating an macro for others.

I am not saying that this is the best way to do it,
it is just an start.

If you have an better way to do it, or other
suggestions, just reply :-)

////Loop through Selection

////Object handling to save always typing of 'document.selection':
var d = document;
var s = d.selection;

////////Get the selected text to work on:
////////(Depends if already something is selected or not)
if (s.IsEmpty)
////If document.selection is empty:
vWasAnSelection = false;

////Alternative one
//alert("Nothing selected, script quits. Please select and start again.");

////Alternative two
alert("Nothing selected, script will select whole text for you.");


////If there was an selection already:
vWasAnSelection = true;
alert("Selected text to work on: n" + s.text);

////////Get start and end line of the selection:
///Returns the line number of the top of the selection.
FirstSelLine = s.GetTopPointY(eePosLogical);
///Returns the line number of the bottom of the selection.
LastSelLine = s.GetBottomPointY(eePosLogical);

////For Each Line In SelectedLineS Do:
for( Line = FirstSelLine; Line <= LastSelLine; Line++)
//// <<< Your code here >>>
//// Here an simple example:
ret = Confirm(d.GetLine(Line));
if (ret == false) {if (!vWasAnSelection){s.Collapse();} Quit();}

////If there was no selection do an UnSelectAll at the end:
if (!vWasAnSelection) s.Collapse();