Write R7 register directly from C

I use KeilC uVision4 for 89C51 MCU.
By "Inline ASM", i can easily direct write value to R7 register, like this :

    #pragma ASM
        MOV R7, #10
    #pragma ENDASM

But now, there are some reason that i have to write to R7 register direct from C (not from inline ASM), eg:

    R7 = 10;

Of course, the C compiler does not understand R7 as MCU Register (not Inline ASM).

-> Is there anyway to solve this problem. Please help me if anyone know, thanks a lot !