Nope and yes.
Nope: ABL statements are executed in the AVM ( ABL Virtual Machine ) which could be the prowin32.exe ( Windows 32Bit GUI version ). Therefore, you can't embedd ABL statements in another language .
Yes: But you can instantiate the AVM via an OS call and have it execute something. Whatever return is needed from that would be handed over by a file generated by the AVM.
Yes: You can directly invoke ABL procedures residing on the OpenEdge AppServer via the .NET Open Client provided by Progress since OE10. You need to build client proxies ( .NET assemblies ) which you can include in your .NET project. In order to build the .NET client proxies you need to use the ProxyGen tool that comes with the developer license - which itself requires the .NET framework 4.0 installed on your machine as it is itself built in .NET.
Heavy Regards, RealHeavyDude.