Input 4 first digit from column A to column B

So you want to access first 4 digits, regardless of what the number is?

Could probably get away with using string functions and literally get first 4 characters out of the string.

PHP Code:

$a = 123486868686868;
$aString = strval($a);
$b = substr($aString, 0, 4); 


All POST data comes in as string anyway, and PHP is quite good at converting types in and out as it is, but I added extra step in there just to point out string conversion.