[Dev-C++] How to convert types?

[<fer...@te...>]

Hi!
I´m trying to use a database, but I need this, I have a field(a year by 
example), it´s a char.
What I need is convert it to an int, add +1 and convert again to char.
It´s a c++ application.

Thanks!

PS: where can I find a guide about functions in header files like 
string.h iostream and others?