I believe Icons are a weak point in LibreOffice because many of them does not suggest the corresponding action.
Moving the mouse over any icon in the ToolBar does not show the function of this icon. This is normal in Open Office (Oracle and Apache)
Is it posible to do this and how?
LibreOffice 126.96.36.199 Portable. Win7 Ultimate
Click Tools - Options - LibreOffice - General and check of Tips.
Sometimes, the impossible can become possible, if you're awesome!
I Thank to John Haller for the inmediate and precise answer.
Windows 7 Ultimate & Windows XP SP3