about memcpy and strcat?

I have again stopped. When I debugging my program, the following function is not working proper. Actually this function runs properly on C, but not in Keil. There are 2 different problems occured.
1) strcat cannot add 2 strings. after strcat no any results.
2) once i merge this function into main function, the second memmmove is also working inproper. The pointer of T and CngStr are becoming the same.
How can I solve it?


char *Change(char *Str){
char *CngStr;
char *T;
int i;char *Change(char *Str){
char *CngStr;
char *T;
CngStr = (char *) malloc (strlen(Str)+2);
T = (char *) malloc (strlen(Str));
strcpy(CngStr,"");
strcpy(T,"");
memmove(CngStr,Str+2,8);
CngStr[8] ='\0';
memmove(T,Str,2);
T[2] ='\0';
strcat(CngStr,T);
free(T);
return(CngStr);
}