According to WineHQ you should be able to run it.
So you should install, open terminal and type:
sudo apt-get install wine
Let the installer finish installing Wine.
And now you can insert the dialbo disk and run the .exe
And if you legally bought Diablo 2 LOD you should have a downloadable alternative on battle.net, which should not ask for a cd when installed.
And you could always download a crack, desperate times ask for desperate solutions.
Wine will now install diablo 2 to it's "c" drive, which is located in
your home folder with the name ".wine". This folder is hidden by
Wine as a program:
When users think of emulators, they think of programs like Dosbox or zsnes. These
applications run as virtual machines and are slow, having to emulate
each processor instruction. Wine does not do any CPU emulation - hence
the name "Wine Is Not an Emulator." Some people argue that since Wine
introduces an extra layer above the system a Windows application will
run slowly. While technically true, Wine is no different from any
other software library in this regard; even newer versions of Windows
must load extra resources to support older applications.