I don't think that it is possible to run the chaining management through method as Chaining management itself a separate utility provided in Demantra.
However you can achieve the same by creating you own custom program to copy the history of a source Item/Site to the new item/site you want to create. You just need to pass the Source ep_id and the target Item/site you want to create as parameters to the program and just call this program thru a Method.
Not sure, if you still have this requirement pending. However, would provide couple of points/options:-
1.Chaining does not only copy the data. It creates the combination as well if the same does not exist. This is largely driven by the scenario.
2.It would be really tough to create the combination wthin Demantra copyting records in MDP_MATRIX.
Chaining as such is not compatible to be invoked through the custom process. I would suggest going for a customization leveraging EP_LOAD to copy the data from one combination to other. EP_LOAD is the safest option to create combinations if you are not willing to use member management and chaining management (you have one more option for Dynamic Chaining/NPI which has limited capability as of now).
Hope, this helps.