I need a lisp routine that will add or subtract to modify a value in a text string. Its used for drainage fixture units on waste & vent plans.
Example:
We use basic dtext strings that look like this 4"(6)
I would like to be able to add or subtract to the number that is ONLY in parenthesis and would like to be able to pick multiple text strings at one time so it would result in something like this:
4"(6) + 9 will become 4"(15)
Does anyone have anything that can do something like this? I have a code that I have tried to modify, but have had no success.