"CLEAR" is not a trigger modifier, it is a trigger by itself therefore you can only use "CLEAR". It is up to the user to decide when to use the CLEAR trigger, it is not fired automatically.
You haven't exactly said, but I am guessing you want to clear the bet ref when your offset bet has been matched. When you set up the Excel link tick "Offset bet matched flag" under "Additional columns". This will output "Y" to column Y (assuming you don't have any other additional columns selected) if the offset bet has been matched. You can then use something like the following formula in the trigger column.
- Code: Select all
=if(Y5="Y","CLEAR","BACK-T3")