Try insert header

Check.pm

@@ -250,7 +250,12 @@ EOF
     my $DUmaxTime      = timeStamp2($Info{DUDailyMaxTime});
     my $DUInodemaxTime = timeStamp2($Info{DUInodeDailyMaxTime});
 
-    my $content = eval ("qq{$Lang->{BackupPC_Check}}");
+    # Show header
+        my $header = <<EOF;
+<p>Header content here</p>
+EOF
+
+    my $content = eval ("qq{$header}");
     Header("BackupPC: Check", $content);
     Trailer();
 }