Hi.
I think it can be done with an IFM plug-in. The ID/labels for observation points are known before the simulation and can be stored in a TXT file. Then, the TXT file can be read by the plug-in, and store the list on a C++ vector. Then, use this IFM command to get the head value at the desired observation points: http://www.feflow.info/html/help/HTMLDocuments/ifm/ifm_api/IfmGetFlowValueOfObsIdAtCurrentTime.htm
Finally, export the output to a TXT file and merge later with X,Y,Z, reference head values.