Configuring Bison to compile an input file under Visual C 6

I'm trying to get Bison to do it's thing in VC6. I'm sure this must be a problem with my configuration. At the moment I have a Custom Build step as follows.

<Commands>
echo Start parser generation  
"C:\GnuWin32\bin\bison.exe" $(InputPath)  
echo Finish parser generation

<Outputs>
$(ProjDir)\$(InputName).c
$(ProjDir)\$(InputName).h

The error I get is "C:\GnuWin32\bin\bison.exe: m4: No such file or directory", which makes me think the m4.exe doesn't exist or isn't on the path, but I can run the exact same command from CMD in the same directory with no errors.

This thought process makes me think it's a problem with the output options, but I've tried various 开发者_开发知识库configurations with no luck.

Any help would be great, thanks in advance.

Edit: I've added some more visual studio versions to the tag list to try to get some more exposure for the question. Hopefully someone will have done this in a later version and I can work backwards.

Okay, I've managed to slove this in a very round-about way but I will try my best to document it here.

It seems that VC6 Custom build options will only look in the project directory for the m4.exe, even when you specify where the calling exe (bison) is explicitly. To solve this I did a bit of a hack and did a full cd command in the custom build window to get to the gnuwin32 directory (where both bison and m4 live) before trying to call the parser generator.

This works fine but is a bit of a hassle for trying to distribute it to other people when they may have installed GNU tools to a different location.