Winapi 32-bit C Programming Issue: Lpdword?

Hi! I am porting some compression code from an old system to WIndows and am having a problem: the ReadFile function is expecting Parameter 4 to be an LPDWORD variable. I was using "&m" as the parameter, where "m" is declared as "unsigned m;". I want to record the number of bytes read for the compression code. I'm sorry for the stupid question, but what is the definition of LPDWORD?

 

DWORD m;
&m

DWORD (double word) aka ULONG, uint32, unsigned int, unsigned long, etc

 

I found my problem: I was declaring the original variable as unsigned rather than unsigned long. I made that mistake because I thought unsigned and unsigned long were synonymous.