HELP! - How to setup GTIN entries using SAP 4.7

HELP--

We are stil on ERP 4.7 and need to store GTIN numbers in Material Master.  There is no configuration in place in 4.7 as there is in ECC6 for this.

What number range  can we use to setup GTIN numbers ( externally assigned) that can range between

00190000000000 (14 characters with 00 leading zeros)  and

30190000000000 (14 characters with 3xxxx at start)

As there already are a number of number ranges defined,  need to know how we can setup on that will work for these

as for maintatining the details - we will have to build a custom table, any thoughts on that?

Thanks,

Bill O.