Any way to amend the multiple extended Warranty programatically

Summary:

Any way to amend the multiple extended Warranty programatically

Content (please ensure you mask any confidential information):

Our customer has a requirement, that we have to create

1. Base Warranty (that is given by supplier)
2. Same date extended Warranty (which is internal and charged to commercial department from Maintenance)

Now, the Base warranty and extended warranty are getting created with the Shipped date of the asset

but customer wants the coverage to start at installed date of asset.

We are able to achieve this for base warranty.

but not for extended warranties.

Is there any way we can achieve this?