Hi George,
thank you for this question.
In general the described behaviour is possible. Connection between HMI and signal in REXYGEN is always one-by-one. You have to introduce subsystem with mask and change the mask parameter via HMI, where the connection string will be as follows:
The masked parameter can be used on as many places as desired within the specified subsystem.
For more information on defining the subsystem mask see:
https://www.rexygen.com/doc/ENGLISH/MANUALS/RexygenStudio/RexygenStudio_ENG.html#x1-340004.2
If you need additional information, let me know.
Regards, Tomas