NAMSTRSUBSFUN, Subscript #nnnn with value vvvv in name specification uses function other than $C/$CHAR/$ZCH/$ZCHAR
GDE Error: This indicates that the nnnn'th subscript in a name specifies a string subscript using an unsupported function. The only two supported functions are $CHAR or $ZCHAR (long form and short forms).
Action: Specify the string subscript using only the supported functions.