SAP PO Installation with Logical IP address

Dear Expert,

We are performing SAP PO NW 7.3 Installation in RHEL environment with oracle 12c.

Landscape :

Clustering : OS clustering.

Server1 host : HostA - Act as a active server

Server2 host : HostB - Act as a passive server

one logical (Host Name :logicalhost) IP bound with above two host (A & B),.

As of now logical IP pointing to HostA.

Installation Details :

1. Run SWPM with ./sapinst SAP_GUI_HOSTNAME = logicalhost (running fine)

2. Then we provide few inputs as per requirement for application i.e SID/RAM size etc..

3. But in define parameter screen for oracle its showing grey field with host name : HostA.

Question :

How can we change oracle host name to logical as this is grey field or is this the correct value for oracle instillation ?