What is the Islamic ruling on buying a house, which is mortgaged to a non-Islamic bank, through Ijarah Muntahia Bittamleek(Lease to own) where an Islamic bank issues a cheque with the value of that mortgage to the non-Islamic bank, then issues another with the rest of the house`s value to the owner. Later on, all parties will meet at the Lands Department to carry on with the needed procedures?