Expression in dmn result variable name

I want to set the result of dmn task in variable with dynamic name. I use this dmn in multi instance task and I want to use element variable of multi instance task as name of dmn result.
I use below syntax for this but the variable name is “${fileId + “-verificationResultRows”}” in database.
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Hey @Mohammad_Mahdavi
you might find this section interesting:
https://docs.camunda.org/manual/latest/user-guide/process-engine/decisions/bpmn-cmmn/#custom-mapping-to-process-variables