Changing the fields in a spreadsheet

Hello,

I am trying to change A,B,C inside the spreadsheet to have a different title. So I want like A to say Measures, B to say Description, and C to say cost. How do I change in from A,B,C to above. I also wish to be able to use $ signs on column C and then add the total to the bottom, right now it just is totaling the numbers together without the $ sign. If anyone could help that would be greatly appreciated. I have attached a screen show of the changes

How do I change the numbers in column C to a currency like $ sign?

To change the text on the Spreadsheet widget header, please add/inject this custom CSS code to the widget:

tbody > tr:first-child {

   background-color: #333;

}

#col_A, #col_B, #col_C {

   color: transparent;

   font-size: 1px;

}

#col_A:before, #col_B:before,#col_C:before{

    color: #FFF;

    font-size: 14px;

}

#col_A:before {

   content: "Measures";

}

#col_B:before {

   content: "Description";

}

#col_C:before {

   content: "Cost";

}

Add the custom CSS code in the custom CSS tab on the widget wizard.