So on a CICS can I change the number that show up say on line 3 to match whats on line 1 in system programming.
My phone company can not do it, so i really want all 4 lines to display the same number on the called partys phone?
Thanks for any help.

Yes, if you have ISDN/PRI service and the service provider has enabled the call screening feature. If this is the case, you can send any number that you like as long as it is associated with the main account.

With POTS lines, no matter which system or brand, this is not possible.

It is my understanding that 'at&t' will mask all lines on the account with the BTN in their Nortel DMS-equipped central offices, but it is done on their end, not from the end-user's equipment.

These are copper lines
Tks ED

Not possible on copper lines. Only provider can change it.