Can you elaborate a bit more about what you are trying to do. If you just want to contrain nodes in one direction you can simply set up a nodal constraint in the desired direction.
If you are looking at a more complex model you can try using gap elements.
There is no such option in any standard linear static FE theory. The direction assymetry breaks the linearity.
In Femap you can still use linear statics by adding gap elements. Or you could move to a non-linear analysis and use either gap elements or contact regions (not sure right now, contact regions might work with linear statics also?).