This is all correct. One detail to note though is that DotName
is a feature in the upcoming release of SystemModeler (of which Neil has a pre-release).
In the released 4.3, you would use period-separated strings instead:
WSMSetValues["junk", {"n" -> 5,
"mass.m" -> {11, 12, 13, 23, 43},
"forceStep.stepForce" -> {1, 2, 3, 4, 5}}]