moving or splicing elements within nested JavaScript objects with string key

I have a nested object I want to manipulate in javascript, splicing an element (and all its children) from one position and placing it in another using location strings to determine the removal and insertion point. I found an question that has several good answer on how access a nested object using a string:

Accessing nested JavaScript objects with string key

(working example : http://ift.tt/1ybxwXk)

but I have no idea how I can adapt this to allow splicing an element from one positions in the object to another. e.g.

var from = "part1";
var to =  "part3[0]

This would remove element at from (someObject["part1"] and re-insert it at to someObject["part3][0]

so if my object looks like this:

var someObject = {
    'part1' : {
        'name': 'Part 1',
        'size': '20',
        'qty' : '50'
    },
    'part2' : {
       'name': 'Part 2',
       'size': '15',
       'qty' : '60'
    },
    'part3' : [
        {
            'name': 'Part 3A',
            'size': '10',
            'qty' : '20'
        }, {
            'name': 'Part 3B',
            'size': '5',
            'qty' : '20'
        }, {
            'name': 'Part 3C',
            'size': '7.5',
            'qty' : '20'
        }
    ]
};

after the slice I would get

var someObject = {
    'part2' : {
       'name': 'Part 2',
       'size': '15',
       'qty' : '60'
    },
    'part3' : [
        'part1' : {
            'name': 'Part 1',
            'size': '20',
            'qty' : '50'
        },
        {
            'name': 'Part 3A',
            'size': '10',
            'qty' : '20'
        },
        {
            'name': 'Part 3B',
            'size': '5',
            'qty' : '20'
        }, {
            'name': 'Part 3C',
            'size': '7.5',
            'qty' : '20'
        }
    ]
};