How do I create a range object when I know just the character offsets?

So I have a div that contains a block of text, previously the user has selected some text in this block and I created a range object from this selection. I stored the offset of the selected text's starting and ending points but I am having problems re-creating the range (so i can manipulate it). "quotables" is the div that holds all the text. I dont know what I am doing wrong.

    var theRange = rangy.createRange();
    var node = $('.quotables').html();
    theRange.setStart(node, 14);
    theRange.setEnd(node, 318);

but I keep getting errors: Uncaught Error: NOT_FOUND_ERR: DOM Exception 8
m.setStart
(anonymous function)
d.extend._Deferred.f.resolveWith
d.d.extend.ready
d.c.addEventListener.y