global vs. local variables in mapping

The situation:

I am going from the source file and splitting the data across five tables which currently works great. The problem I am having is I need to generate an id that ties all the tables together and then reset that id for every file.

I have created a C# class that keeps control of the variables and increments them for the destination which works great as well.

The problem I am having is getting the variables to reset for every file. There is nothing being mapped that is unique to get the variables to reset per file. So I created a c# scripting functiod that did the incrementing thinking that it would reset it self since it a local function. The problem I am having with this is the counters are resetting themselves with every call so all of my counters are 1 and never increment.

I have also tried resetting the global counters by calling a c# class that i created called ResetGlobalCounters and this just does not work.

I am a programmer by trade and new to this biztalk stuff and I am having a real problem understanding how this orchestration and mapping uses and stores variables. I have several books but none of them get into real detail.

Any suggestion would be much appreciated.