Custom Rules on properties with !Sub

[manraog]

Hi.

I'm trying to create a custom rule but the propertie has a !Sub.

I have tried without succes:
AWS::Lambda::Function FunctionName.Fn::Sub REGEX_MATCH "(^[a-zA-Z0-9_-]{0,15}\$\{EnvName\})?" ERROR "Name too long"
AWS::Lambda::Function FunctionName."Fn::Sub" REGEX_MATCH "(^[a-zA-Z0-9_-]{0,15}\$\{EnvName\})?" ERROR "Name too long"
AWS::Lambda::Function FunctionName.'Fn::Sub' REGEX_MATCH "(^[a-zA-Z0-9_-]{0,15}\$\{EnvName\})?" ERROR "Name too long"

Do I need to create a totally new rule?
https://github.com/aws-cloudformation/cfn-lint/blob/main/docs/getting_started/rules.md

Thank's in advance