Extra Invoice Type

Hello dolibarr community,
here’s my problem:

Now, in Dolibarr, there are some predefined types (Invoice Standard, Invoice Deposit, Invoice Pro Forma, Invoice Avoir…)

There is also an automatically generated id for each invoice. (i can set different series, one for standard invoices and one for InvoiceAvoir. but invoiceAvoir creates a different Pdf (with negative prices))

What I need is 2 different series of Standard Invoices. For example some times i want the id to be A-{0000} and some other times to be B-{0000}.

Can this be done easily? If not, what I thought was having one more invoice type, called let’s say InvoiceStandard_new, which will take id’s from another mask (B-{0000} in my case) and create pdf’s just like the InvoiceStandard ones.
As far as i looked, this can’t be done unless i change the php code. is there an easy way to do this?

Thanks for your time,
Thanos

dp you have resovled? i need this solution fo rme