1>LINK : fatal error LNK1104: cannot open file 'libmatlb.lib'

I'm using MATLAB compiler to build a DLL, lib and h files from some older MATLAB source code that was originally built into a DLL using MATLAB 6p5.

I've rebuilt the same old source code using MATLAB 2013b without any issues but when I use the new DLL, lib and h files in an application I get this linker error

1>LINK : fatal error LNK1104: cannot open file 'libmatlb.lib'

I have searched the MATLAB program folders (in x86) but this lib file does not appear to exist anymore. I don't have access to 6p5 anymore. Does anyone know where I can get a copy of this old lib? Does anyone know what functions are in this lib so I might be able to replace it with some other more modern lib file?

Any thoughts at all would be appreciated, thanks!