No that's not what you should do, the new sts should be one both sides of the original sts, making a T shape and will make the front and back. Cast on using the knit (or cable) CO, and you're still at the beginning of a row. Knit over the new sts, knit the 36 sts and turn. CO the other 34 sts and you now have 104.
sue- knitting heretic