If I read this correctly, you are referring to entering good and bad into the var field within the dynamic text properties box.
However, it is possible to have the text box display a variable through as2.
For example, you could place a dynamic text box and give it the instance name score_txt
You could have the text box update automatically with each frame, by typing the following into the actions window of the main stage:
score = 0
onEnterFrame = function (){
score_txt.text = score
}
Or, you could have the text box update every time the variable is changed. You could create a movie clip with the instance name "coin_mc" Then type this one the main stage:
coin_mc.onPress = function (){
_root.score += 5
_root.score_txt.text=_root.score
}
If you choose to use the first option, simply remove the "_root.score_txt.text=_root.score" from the second, but use the rest.
I hope this helps to solve your problem