Ok so I am developing an Excel addin that analyzes text in a cell then converts it.
I want it to work like things do in excel like absolute value when you can type into a cell =abs(YOURNUMBER) and then it will replace the text of the cell with the absolute value of your number.
How do i set up the excel add in to add a custom option that would accept strings in a fashion like this, except using =molem(YOURSTRING) instead?
It sounds like you want to make an Excel user-defined function (UDF) using C#. The best way to do this is to use the free Excel-DNA library (which I develop). This will allow code like this:
to be used in your worksheet as
=molem("Some String").