Would you believe my machine doesn't have a simple satin stitch either? lol It does have a satin-style stitch, but it makes little 'pyramids' with the stitch as it goes along (not sure how to describe this properly, but essentially it is a decorative stitch, not a functional one!)
I ended up using a zig-zag that is enclosed on each side within parallel lines - fancier than intended, but oh well
(maybe I should add that my machine is a cheap Brother with a total of 34 stitches available - I like it as a machine, but the stitch selection tends towards the fancier end to my mind
). Normal zig-zag (which it does have, ha) didn't look right to me on the applique.