I am thinking the question stands well enough by itself, but I will give background for the record.
I have a C# project in VS 2012.
It's a cross application application.
In other words, I am gathering information about multiple open applications running on a machine.
As part of that, I was using SapROTWr to collect information about which environment, client and transaction a user had running.
I was having to compile my project as 32bit.... as the above dll is 32bit and will not compile in a 64 bit project.
However, I now have a need for some 64bit functionality.
This part is nothing to do with SAP or it's products, simply that my application needs to talk to other applications and access their window processes.
For example, I wish to get the MainModule information from an IE process which is running as x64.
For that I need 64 bit compilation.
So now I hit a block.
I can compile 32bit and utilize SAP's Interop OR I can compile 64bit and speak to all my other applications.
But not both at the same time 
I am looking into a workaround for the other apps, not sure if possible or not, the signs so far are not good.
If there was a 64bit version of the SAP library, it would make life happy again !!
Many Thanks