Thanks a lot for your help while I was waiting for your response I did the following that worked, basically is the same method. Suppressing the box is one extra step to make sure no other interference.
I created a Text Box in the header and opened it for format clicking on suppress code box and put the following; (if it is working correctly) it is suppressing the box just after variable R value is set. I call the variable in other part of my program and it is keeping the value.
stringVar R;
R := Right({Table9.SubNo},1); //Getting the last character into the variable
IIF (R<>"",True,False) //Suppress the box
Once again I thank you for your time and help.