How to separate char from an input text box?

[Deib]

I want to make a VIN decoder.
I know what each digit means, but how do I separate the digits from the input box?

So I have a box that the user inputs a 17 characters.

How do I separate the digits into T1, T2, T3 ect for all 17 digits?

Does that make sense?
So the user will input "abcdef" into a box and hit submit.
I want to separate a=T1 b=t2, c=t3
The 17 character input will never be the same.

Once I separate those out I can use simple if then statements to finish the rest.

I am sure this is simple but you would be my hero.
Thanks.