Can I create a JobCost to SAGE CRE by using .NET COM object in C# without using .NET SDK?

Hi Expert

I have been put it into a project of SAGE CRE where I need to create a JobCost in SAGE CRE. 

Only thing that I have is that the COM Object and other dlls . Is there any way to create a JobCost without using SDK?

The following dlls I am having : 

Interop.JCCOMBusinessLayer, Interop.JCCOMSharedTypes, Interop.tsAuthInterfaces, Interop.tsAuthUI, Interop.tsComUtils, Interop.tsDataConnection, Interop.tsMiddleLayerBusiness,

Sage.Business.CRE, Sage.Business.CRE.Core, Sage.Data.CRE.JobCost and Sage.STO.CloudIntegration.

Is it possible to connect to SAGE CRE (for example : by creating Session) and create a JobCost to SAGE CRE by taking the references from the dlls?

If yes, Please suggest which interface or class will solve my problem.

Thanks 

Avijit Paul Poddar