Special character on varity of BOCA models

We have been attempting to insert the R (registered) and sometimes crtl+0169 works and sometime ctrl+0174 works depending on which printer is being used to print the tickets (we are using the font 13 as directed in documentation). We have equal numbers of two different models.
Is there any kind of absolute value or wildcard that would use so each printer gets what it needs to print this character?
Thanks in advance for the help.
Tina