use strict;
use warnings;

while ( <DATA> ) {
  my $string = $_;
  if ( $string =~ /func[A-Za-z]\(
        (func[A-Za-z]\([^\)]+\)|[^,]+)         #looks for a function and if not found then
       ,(func[A-Za-z]\([^\)]+\)|[^,]+)        #grab everything to the comma
       ,(func[A-Za-z]\([^\)]+\)|[^,]+)
      ,(func[A-Za-z]\([^\)]+\)|[^,]+)\)/x)
  {
    print "FOR STRING: $string",
          '$1 = ',$1,$/,
          '$2 = ',$2,$/,
          '$3 = ',$3,$/,
          '$4 = ',$4,$/,$/;
  }
}


__DATA__
funca(1,2,3,4)
funca(funcH(A,B,C),2,3,4)
funca(1,funcH(A,B,C),3,4)
funca(1,2,funcH(A,B,C),4)
funca(1,2,3,funcH(A,B,C))