one docment type with 2 different no.range used for 2 different customers

Hi All,

one document type with two different number range. 2 different customers A & B and everything is under one company code. when i post invoice to customer A it should pick from first document number range and when i post invoice to customer B it should pick from second document number range. both no. ranges are in same document type. please share ur thoughts about configuration in SAP. usually system will pick the lower number availabe in the range.

How to call second number range for B customer?

thanks in advance.