ABAP supports the OLE2 automation technique, applications like Excel and Winword can be integrated with SAP using OLE2 automation Server.
Pre-requisite:
Applications controlled by ABAP must be registered in R/3.
Please see the diagram given below.
For more details see the links given below.
SAP OLE AUTOMATION PART 1
SAP OLE AUTOMATION PART 2
SAP OLE AUTOMATION PART 3