From Ciaran on the XSI mailing list, here’s a good example of how to find all light nulls whose names contain “lamp” or “light”:

oLightNulls =  oModel.FindChildren2("{*light*,*lamp*}",c.siNullPrimType)

The curly brackets {} are used in a string expression to specify a list of objects.

That String Expressions page still looks pretty much the same as it did back in 1999, when I first wrote it!