Do some Excel Work

Our business needs a new excel form, we sell campers and sporting goods. This form will only be used as a purchase agreement (tax purposes)or quote, as we have a full functioning Point of sale. -The form needs to be able to calculate Taxes and fees automatically. -Calculate Finance rates and payments bases on credit score. -Have the ability to to have both in and out of state options. The form needs to be revamped with added functionality. A good knowledge of macros will be needed, functionality is more important that appearance I will be able to send a complete list of options. See the current working form that can be used as an example