I have a string of *8 separated hexadecimal numbers*, such as:

```
3E%12%3%1F%3E%6%1%19

```

And I need to check if the number `12` is located within the *first 4 set of numbers*.

I'm guessing this shouldn't be all that complex, but my searches turned up empty. Regular expressions are always a trouble for me, but I don't have access to anything else in this scenario. Any help would be appreciated.