在header中搜索Word并设置列用于Excel VBA中的计算

I am attempting to carry out calculations on columns in an Excel spreadsheet. The column names are: LowLimit, HighLimit and MeasValue "I am only able to right now 'hard code' the column numbers to carry out the calculations (as shown in the code below). The code works great if the column positions remain the same. However, the position of the columns changes throughout the workbook but they are always in the same order. For example, on sheet one, the headers LowLimit, HighLimit and MeasValue will be in positions J, K, L respectively. On sheet 25, they will change positions to G, H, I respectively. I am attempting to carry out calculations on co