i need to know how i would have an array of letters/numbers, and when i read it, if it finds a letter, changer it to a number, heres what i have... the ****** is where i need help.

#include <iostream.h>
#include<apvector.h>

char number[25];
char NewNumber[25];
int main()
{
int i;
cout<<"Enter the phone number ==>: ";
cin.getline(number,80);

for(i=0;i<26;i++)

*********find if letter, make it a number i.e. a,b,c, = 2**********
cout<<number[i];


cout<<"\nThe original number is : "<<number<<"\n";

return 0;
}

thanks