build regex in perl

I'm using pgFormatter to format PostgreSQL files. pgFormatter uses perl. pgFormatter replacing some part of SQL code.

To prevent replacing , pgFormatter provided Perl regular expression.

SQL Query

select STRING_AGG(', string_agg(case when at_type_name='''
    || at_type_name||''' then value_'||value_type||'::text end, ''||'') as "'
    || regexp_replace(at_type_name, '\m' ||obj_type_name_rm_prefix, '','i')||'"','')
    from ( select distinct key,at_type_name from table1
      where status='active' order by at_type_name) as fg)as fb;

pgFormatter replacing below lines in above code. I'm trying build RegEx in perl for below

as "'
    || regexp_replace(at_type_name, '\m' ||obj_type_name_rm_prefix, '','i')||'"','')

I started build regex as "'.*\n , but don't know to build till end ,'') .