Apache velocity get user input and put it into ${NUM_VAR} and ${NUMERIC_VAR}

So I have this problem: 

// / * Workshop - #${NUM_VAR} (Part-${NUMERIC_VAR})\n

${NUM_VAR} and ${NUMERIC_VAR} are supposed to be variables into which I will put a single digit. I also want the mouse to be put into each of the variables for me to put said digits in. However when I try to use the template, it just dumbly prints the template, disregarding the fact that ${NUM_VAR} and ${NUMERIC_VAR} are supposed to be variables. When I try to validate it, it says this a valid use of the template: So what am I doing wrong?