Excel Invoice Template to Acrobat Pro 2017

I need to convert an invoice template in excel to PDF. I have two questions:

1. This excel formula needs to be converted into JavaScript.

      =IF(SUM(N53,-Q53)<0, "$0.00", SUM(N53,-Q53))

          I tried a formula converter and replaced N53 and Q53 with Text1 and Text2 and I could not figure it out.

2. I want to know if I can make a field required under certain conditions. Say I enter a dollar amount and want to know if the service was performed in CA or in the US I want the consultant required to check the option that applies.

However, there may be extra lines that are available to enter amounts but not completed because they only need a few lines. Can I have a required field with an if statement for the other lines available but not in use, so it will not be required if certain fields are not completed.

The only way I can work around this is putting a N/A option but then they would have to complete all the lines that are not in use.

I hope I can find some help here with these two issues. Thank you for your support.