How to translate this C++ preprocessor declaration in D?

[Heinz]

> If it really has single quotes then it is a multi-character 
> literal, value of which happens to be implementation-dependent. 
> What is actually in place of asdf there? May be we can guess 
> the intent better.
>
> Ali

Here're some examples:

#define	kPIHostBlendModeSignature	'8BIM'
#define PIPowerPCCarbonCodeProperty	'ppcb'
#define PIPowerPCMachOCodeProperty	'mach'
#define PICodeMacIntel32Property	'mi32'
#define PICodeMacIntel32Property	'mi64'

I'm porting the Photoshop SDK (CS6) to D. I already compiled a 
hybrid plugin with DMC and DMD (it works) but now i want to make 
native D plugins.