Converting CString to int ??

Hi..
I'm using Visual C++
in my text box i assign a CString variable
and i want to convert it to integer. How can i do it ?
CString = "5+5*5"
converts to
int = 5+5*5


actually i have assigned before a int variable to the textbox
but when i insert 5+5, the int variable only contain 5 not 5+5.
so i assigned a CString variable

Please help me, and thanks you very much.
i'm planning to make a calculator for my course's project.

Well i already tries atoi() but it just didn't work.
i think it can't convert the arithmatic operator (-,+,*,/)
plssss help me...

Use atoi, get all the numbers, then go back and get the operators. Then, do the arithmetic operations on them. A useful function for this would be strpbrk()

i still confused ????
the problem is visual c++ can't read if we input "5+5" for integer ?