What does the following below mean?

ELSE
 $number=$number*Power(10,1)
 $number=$number+$currentnum
 $order++
EndIf

What if you wanted to shift or move down the input data to another string variable? Would that depend on the $order string variable right?

IF ($order=0)
$number=$currentnum
$order++

$order++ means you are adding the number one to it right

The first section of code can be replaced to

ELSE
 $number=$number*10
 $number=$number+$currentnum
 $order++
EndIf

you don't need the power function... but what this does is when you press a key it will move the first number entered to a new column and then add the new number pressed.

so if you press 1 the entered number is 1 if you press 2 the entered number is now 10+2=12 if you press 3 the entered number is now 120+3=123

that way it is just like a calculator when entering numbers on the keypad.

the entered number is stored in $number you can store this value in a different variable if you wish but it would be an integer to start not a string. and order++ increases the amount of digits stored in $number... so by resetting order to 0 you enter a new number into the $number variable.

How would you store $number into another variable after you are done entering it?

a script to look at the count?

$newvariable = $oldvariable

So...

$anothervariable = $number

You would create an enter button that signifies that you are done entering a number and then you would do as Rich said to store the value in another variable.