How To Get Numetic Value!!! using C ???

Hi All!

I want to GetValue numeric type from binary cursor, but I have no ideas
how to do it.
Now I am using

double test;
test=atof((char*)GetValue(0,0));
in C function and doing
to_char(my_numeric_field, '9999999999999D99')
in database selection.
May be there is another normal way to do it.

Thanks a lot!!!
Oleg Shalnev