You can incorporate legislation into a contract but you cannot attempt to bind non-consenting third parties, like the state or its regulators, by incorporating legislation. Obligations cannot be imposed on private third parties without their consent.
For example, the parties in Firstrand Bank v Clear Creek Trading concluded a contract to which the National Credit Act did not apply. The agreement stated that the NCA applied, and included various references to the act. If the NCA did apply, the National Credit Regulator could become involved if there were a dispute on the contract. But the credit regulator, as an entity created by the act, is not capable of dealing with an agreement to which the NCA would not otherwise apply. Therefore that part of an act which involves a regulator cannot be made applicable to an agreement not otherwise governed by the act. Also, the machinery of the state cannot be burdened by matters to which the statute is not intended to apply.
If the whole of an act cannot be made to apply to an agreement, the parties must specify which provisions are applicable.
The court in Clear Creek did say that the law is not settled as to the effect of attempting to make legislation as a whole applicable to an agreement if certain parts of the legislation cannot be invoked. It seems that if the clauses incorporating the inapplicable portion of the legislation can be severed from the agreement and the agreement still makes sense, the clauses may be severed. But if the rest of the agreement reflects the intention of the parties that those clauses are integral to the contract, the contract as a whole may be unenforceable.