C/C++ gurus ! help ! - dStrrchr is always const char

Hello C++/C gurus !

There are two versions of dStrrchr():

char*       dStrrchr(char *str, int c);
const char* dStrrchr(const char *str, int c);

i'm think i'm having trouble getting VS7 to believe that i want the char*, not the const char*.

with the following code i get "error C2106: '=' : left operand must be l-value".
how can i elegantly get it to do what i want ?

char buf[128] = "blahblah.foo";

// "=" gives l-value error on left operand:
dStrrchr(buf, '.') = '[[60c1fa3019d69]]';

// gives the same error:
(char*)(dStrrchr((char*)pathBuf, (int)'.')) = '[[60c1fa3019d69]]';

// this works, but it's ugly:
buf[dStrrchr(buf, '.') - buf] = '[[60c1fa3019d69]]';

// this also works, and isn't so ugly, but makes me feel bad about myself:
char* ret;
ret = dStrrchr(buf, '.');
ret = '[[60c1fa3019d69]]';

i've tried casting dStrrchr to char* as well as casting buf to char* in the call to dStrrchr.

tia,
orion