C++ does not let to express voids naturally

[EverBeginner]

Hello EverBody,

I am trying to express naturally:

void __stdcall
functWrite_ItUp(void* ptrROW)
{

(byte*)ptrROW[0]='A';
(byte*)ptrROW[1]='B';
(byte*)ptrROW[2]='C';
};

but a C++ compiler is giving error message:
Expressions of type void cannot be converted to other types.

Looking forward to read from you a help.

[Bazzy]

Add some parentheses: ( (byte*)ptrROW ) [0]='A';

[EverBeginner]

Thanks.