It'd be slower, but what about creating a new $base called $basepc for base precision in which it'd do it in a long-hand method while keeping the current $base that is used in 6.1 and higher (for speed purposes)?
This topic has indeed been discussed many times before, ie. adding support for arbitrary precision arithmetic, such as BigNum. There is no practical way to add support for this since the result would not be usable anywhere else in mIRC, as no other feature would be able to parse that value, use it in a calculation, etc. Every scripting command/identifier would eventually need to have its own $XXXpc() extended version to handle BigNum values, and because the scripting language is so closely tied to whole of mIRC, including the GUI, every scripting feature would need to perform conversions from BigNum to non-BigNum values in order for the values to be consistently usable everywhere else, with the resulting decrease in performance due to BigNum handling.
