The "XV SteelGtr1" should give you the slide effect. Make sure you're hitting the key hard enough; it takes a pretty good strike. Maybe try adjusting the key sensitivity.

The "XV SteelGtr2" does not have the slide effect. However, another one to try is "DoubleSteel" (User 062); it has similar characteristics to SteelGtr1.

Two others to try are "Comp'Steel" and "Folk Guitar" (Presets F 035 and 037 respectively). These ones don't have the guitar harmonics but do have the slide.

I hope this helps.