User Exit for Number Range of Specification Master

Dear Experts,

Is there user exit for number range of spec master?

I want to realize spec master numbering by internal numbering with alphabet like below.

Alphabet is not allowed for internal numbering, therefore additional logic have to be implemented.

Spec type Number Range

Z001 A00000000000 ~ A99999999999

Z002 B00000000000 ~ B99999999999

...