Asset settlement with two different GL

Dear All,

In Construction business they are create one road/bridge etc. after construction is completed they settled total amount include of subsidy amount given by government to final in intangible asset. Here the actual problem is they want to bifurcate the amount which was subsidy given by government in to different GL i.e. Capital Reserve and Amortization should be calculate with two amounts in asset value and subsidy value.

Exp:

Asset under Construction value 100000 (WBS)

Subsidy given by Government 50000 (WBS)

When settling WBS element to final asset in asset master both 100000+50000=150000

But background GL should be 100000 is Asset GL and 50000 is Capital Reserve GL

How can I configuration this in SAP could anyone help me on this.

Thanks

Swamy