I am working on a patter that has called for 88 stitches to be cast on. After working several rows you put 23 stitches on a holder, 42 stitiches on a holder and knit the last 23 for a certain length. This was bound off and the pattern says to put the 42 sts back on the needle and join yarn and knit to same length as above. My question is how do I join the yarn? There is no tail or side seam to join to.