Use token value to set another token by using replace

Hello, I try to using the token set up in a checkbox who will create a token like that: (" F " OR " E " OR " W ") this token will be used as filter on _raw data but i want to use the token information to refine the search after a rex where i create a column call errorlvl so i want to convert the value of token by using a serie of replace to something like this : (errorlvl="F" OR errorlvl="E" OR errorlvl="W") I already know the replace the sequence to use but I have a issue to create in simple xml. Could you help me ? Thanks