Temperatura - HELP

Hello everybody.

My name is Pedro Santos and I am a student of Eng. Instrumentation and Metrology in ISEP, Porto, Portugal.
I am developing my project / traineeship and I am in need of some help on the Arduino.

Until now developed my electronic circuit, and my temperature sensor NTC transistor.
I have voltage changes the output of my circuit between 0 and 5V.

I now want to turn that same output voltage to an analog input of the Arduino and then using a formula intend to convert this tension in temperature, for example:
Temp (°C) = 0.2 V^2 + 5.2V, where V is the output voltage of the circuit.

After intend to save to PC the values ??of temperature to a notepad of 15 to 15 minutes, and the same three columns comprising:
1st column for the date;
2nd column for the Hour;
3rd column referring to the temperature read
eg
05.23.2013 10:00:00 21 ºC
05.23.2013 10:15:00 23 ºC
05.23.2013 10:30:00 25 ºC

Grateful if I can help in total programming Arduino, because I never worked with the same ...
Thank you!

Pedro Santos

Hello Pedro
I didn't understand if you already done this or not?

05.23.2013   10:00:00   21 ºC

Did you already have this working?
Where you need help?

HugoPT:
Hello Pedro
I didn't understand if you already done this or not?

05.23.2013   10:00:00   21 ºC

Did you already have this working?
Where you need help?

Não não consegui, mas é esse o tipo de formato que pretendo que seja guardado no bloco de notas.

No, i didn't, but this is the type of format that i want to be saved in notepad.