I am new to power query and need some help. I have 25 columns and 10k rows table with value data in it. I want to create custom column which will result the sum of specific range of columns. i.e. sum of the data from 3rd column to 10th column. I wish to have this formula dynamic, means the range of number of columns (above I have selected as 8 ) will vary every month. I could achieve it thru "Offset" function in excel but not able to do so in Power query. Please advice.