I am working on this new project to do some arithmetic operations on the data provided in an excel file. I completed the arithmetic part, but when I run it an error pops us saying ** "Input string was not in a correct format"**. My data is of many numerical values, I have to do some addition, multiplications, percentages etc.

With some googling I did found using ** "regex"** is an option to solve this. But unfortunately I am not used to that. Could anyone please help me with this error, as I am not sure where to put the regex and How!!!

thanx in advance