Yes, there is an easy way to convert a column of monthly data into a column of quarterly data in Microsoft Excel. Here are the steps:

1. First, create a new column next to the column of monthly data.
2. In the first cell of the new column, enter the formula
   Code:

   "=AVERAGE(A1:A3)"

   (assuming the monthly data is in column A and the first month is in cell A1). This formula will average the first three months to give you the first quarter value.
3. Copy the formula down to the rest of the cells in the new column. Excel will automatically adjust the formula to average the next three months for each subsequent quarter.
4. Finally, format the new column as desired (e.g. as currency or percentage).

That's it! You now have a column of quarterly data that represents the average of the months in each quarter.