I don't know of a GUI program to do it, but there probably is somewhere. The bigger question is why would you want to go to the trouble of downloading and installing a GUI program to do something that is so simple to do from the command line?
Let's say that you want to put grub on the sda5 partition. Open a terminal and type:
That's it. You have just installed Grub to sda5 pointing to the menu.lst located in /boot/grub of the / partition on sda5.
Insanity: Doing the same thing over and over and each time expecting a different result.
Democracy is 2 wolves and a lamb voting on the menu. Liberty is an armed lamb protesting the electoral outcome. A Republic negates the need for an armed protest.