Can you explain again what's the problem, please. I didn't understand it.
BTW
cFreezeTime = 1 why you use get_pcvar_num, it's not cvar.
Why you decrease the value with 0
iScreenTime = 0
(get_pcvar_num(cScreenTime) + get_pcvar_num(cFreezeTime)) - iScreenTime
Also you use ( ) for addition and subtraction, why ?