I am trying to subtract one column from another and want to do it for other columns as well by using foreach

My data is like this Column1 Column2 Column3 Total I am using the below command **|foreach Column* [ eval Answer <> = Total - <> ] |table Column1, Column2, Column3 Answer1, Answer2, Answer3** but I getting the below error *Error in 'foreach' command: The last argument must be a search pipeline* ![alt text][1] [1]: /storage/temp/218655-splunk-error.png Kindly Help me with this issue.