We'll need more information if you expect a coherent response.

You don't say why 30101/100 is correct and 301010/050 is incorrect. Is it
down to the number of digits?
Are they both account numbers or is part of it the product code?
Why have you listed errors as well as correct codes? All you need is the
"good" list, everything lese is wrong (or vice versa).
You say the balance sheet a/c nos start with 1 or 0, then go on to state
that a number beginning with 0 doesn't exist. Why doesn't it?

On a more constructive note, perhaps you need to look at data validation so
that the account numbers & product codes are not typed in, but picked from a
list.