Sure, no problem. You can just assign it directly to a variable:
volatile unsigned int *myPointer = (volatile unsigned int *)0x12345678;
What I usually do is declare a memory-mapped I/O macro:
#define mmio32(x) (*(volatile unsigned long *)(x))
And then define my registers in a header file:
#define SFR_BASE (0xCF800000)
#define SFR_1 (SFR_BASE + 0x0004)
#define SFR_2 (SFR_BASE + 0x0010)
And then use them:
unsigned long registerValue = mmio32(SFR_1); // read
mmio32(SFR2) = 0x85748312; // write