Pb with msgbox

Hi everybody
I would like to display a kind of array (cf. below).
I have tried this:

msgbox({'         --------------------';
'         | mean | min | max |';
'|----------------------------';
'| param1 | 12.5 | 2.0 | 25.2|';
'| param2 | 14.5 | 1.0 | 32.5|';
'-----------------------------'},'Title');

But it's not displayed as I would want because the font used has not a fixed
width.
How could I do?
Thank you

Zlika