Relative Cell Reference For Summing

This is one of about 25 sheets in one excel file, and I will be receiving about 5 different files a week, so a macro is necessary to save time. I tried to create a macro just by recording, and it was not able to adjust to the variances in the number of lines between the sheets.

I need it to do the following, and more or less in this order:
-Delete Column A
-Create text and format A1:C1
-Sort rows 2 through the last row based on column C values (from largest to smallest, although its not shown in the picture above)
-Create a sum at the bottom
-Apply grid lines to all the data

I don't have a problem with the first two, but I cannot figure out how to adjust for the number of rows for sorting, offset 1 cell down to create the sum formula below the data, or how to properly write the macro for the sum formula itself. When I recorded the macro, it used cell references like Range("C5").Select and others which do not adapt to the varying number of rows.

I tried using the offset command in this thread without much luck.

This is some of the macro I have:


Columns("A:A").Select
Selection.Delete Shift:=xlToLeft
Range("A1").Select
ActiveCell.FormulaR1C1 = "Customer ID"
Range("B1").Select
ActiveCell.FormulaR1C1 = "Customer Name"........