Aside from the technical method to do what you want...Could you help me understand why? Not trying to be antagonistic, just enhance my knowledge. I understand the assignable causes for a trend may be different than a point OOC, but the charts are just meant to help identify those, you still need process knowledge to determine what the causes are in any case.
AFAIK, Shewhart did not propose differentiating the different tests. These were established by a group at the Western Electric Company in 1956. They were intended to provide guidance and perhaps enhance our ability to identify unusual patterns in the data presented as a time series (over and above the control limits interpretation). I'm curious as to why you would differentiate what "rule" was used to identify unusual patterns as evidence of assignable cause variation? Also the rules often do not apply to 1 point. For example, on a MR chart an OOC condition is a function of 2 data points. A trend is a function of 7 data points...etc.
"All models are wrong, some are useful" G.E.P. Box