How to Print to the Console

Question

Background:

Using the settings under Edit-> Preferences->Evaluation I can redirect all the Print statments to the console.

What I'd really like to do is redirect just some specific Print statements to the console. I know I can print to another notebook with something like:

PrintToNotebook[nb_, expr_] := ( 
   SelectionMove[nb, After, Cell]; 
   NotebookWrite[nb, Cell[BoxData[ToBoxes[expr]], "Print"]]) 

So perhaps this boils down to finding the "Console Handle"?

Question: How can I create a function (eg PrintToConsole) that behaves like Print but outputs to the console?

EDIT

Turns out the trick is in MessagesNotebook[]. This is what I'm currently using

ClearAll[PrintToConsole]
$OldLine = -1;
PrintToConsole[
   expr_] := (SelectionMove[MessagesNotebook[], After, Cell];
   NotebookWrite[MessagesNotebook[], 
    Cell[BoxData[ToBoxes[expr]], "Print", 
     CellLabel ->  "During evaluation of In[" <> ToString@$Line <> "]:=", 
     ShowCellLabel -> ($OldLine =!= $Line)]];
   $OldLine = $Line;);
PrintToConsole[
   expr__] := (SelectionMove[MessagesNotebook[], After, Cell];
   NotebookWrite[MessagesNotebook[], 
    Cell[BoxData[ToBoxes[Row@{expr}]], "Print", 
     CellLabel -> "During evaluation of In[" <> ToString@$Line <> "]:=",
     ShowCellLabel -> ($OldLine =!= $Line)]];
   $OldLine = $Line;);

Answer 1

The "Messages" window or the console is just another notebook, referenced by MessagesNotebook[]. So to print directly to that, use:

Clear[PrintToConsole]
PrintToConsole[expr_] := (SetSelectedNotebook[MessagesNotebook[]]; 
    NotebookWrite[SelectedNotebook[], Cell[BoxData[ToBoxes[expr]], "Print"]])

This will print to the console and also brings it to focus. To make the notebook visible if it already isn't, add SetOptions[MessagesNotebook[], Visible -> True] in the definition above. However, I don't think that either of them are good UX, because it might get annoying if you're printing something continuously, and want to work in a different notebook in the mean time.

---

To get the same behaviour as Print with the During evaluation of... lines printed, use:

Clear[PrintToConsole]
PrintToConsole[expr_] := (SelectionMove[MessagesNotebook[], After, Cell];
    NotebookWrite[MessagesNotebook[], 
        Cell[BoxData["During evaluation of In[" <> ToString@$Line <> "]"], "CellLabel"]];
    NotebookWrite[MessagesNotebook[], Cell[BoxData[ToBoxes[expr]], "Print"]])