Arduino and ATTINY2313.

Hello everyone!
First of all, congratulations about your site.You have some really nice projects that i'll try to make at the future.

I would like to ask you some questions.
I have recently bought the arduino mainboard with the Atmega328.
My question is if i can put another microcontroller,specifically the atmel ATTINY2313-20PU and in which pins of the board.
Secondly, can i load a .hex file(with C) on the ATTINY2313-20PU and how that can be done?

Thank you.

The ATMega328 is a 28 pin chip. The ATTINY2313 is a 20 pin chip. Just as a guess, I'd say that they are not interchangeable.

Secondly, can i load a .hex file(with C) on the ATTINY2313-20PU and how that can be done?

Hex files don't contain C code.