Yes there is a list of expressions - Tools - Expressions or Information - Expressions.
The post needs to know what the names of the expressions are before you can get the values. A more elaborate method would be to create a UDE where you can input the expression names and then output the values in the post. Either way you will still need to know the expression name. yes it's a bit tricky.
John Joyce
N.C. Programming Supervisor
Barnes Aerospace, Windsor CT
NX6.0.5.3