Armed with nothing but a hex-editor, I've managed to get the Kilrathi Saga WC3 working with Mash's patch and ddhack... Strangely enough, ddhack by itself won't work on my XP environment, but runs combined with Mash's patch? (I get a black screen if I tried ddhack on its own)
This is what I did...
1. Download Mash's patch and extract to my C:\Program Files\Kilrathi Saga\WC3 directory. Rename his ddraw.dll to mashp.dll
2. Hex edit WC3W.EXE, replace all instances of ddraw.dll with mashp.dll (should be one occurence)
3. Test WC3W to ensure Mash's patch is taking effect.
4. Download ddhack and extract to the Kilrathi Saga WC3 directory.
5. Rename the ddhack ddraw.dll to dhack.dll. Move only that file to C:\Windows\System32 (or whatever Vista/7 equivalent)
4. From what I understand, Mash's patch intercepts the game's DirectDrawCreate call, does its thing, then makes DirectDrawCreate call from the real ddraw.dll. It specifically gets the system path using GetSystemDirectoryA to load the real ddraw.dll...
5. I then hex-edited mashp.dll, replacing all instances of ddraw.dll with dhack.dll (should be two instances)
6. Now, with Mash's patch looking for dhack.dll from the system directory, it somehow successfully loaded ddhack. Note that the ddhack config file needs to stay in the WC3 directory.
Haven't played it for any extended period of time but it seems to work fine. Proceed at your own risk :)