I have a dotnet assembly which includes classes RequestType, Response,
Transaction, and TransactionElement.

To use this I would normally create a new Transaction passing it a parameter
of RequestType and receive a Transaction object of the right type in return.

Paymentech.Transaction transaction = new
Paymentech.Transaction(Paymentech.RequestType.CC_AUTHORIZE);

I now find myself having to access this assembly in an environment that does
not allow me to pass the RequestType parameter when I create the object
(PHP). To work around this limitation, I would like to create another dotnet
assembly which will basically be way to call all the different types of
Transactions without passing parameters. In other words, I want to create a
separate class for each type of Transaction I need.

So I will end up with a CC_AuthorizeTransaction class, a
CC_CaptureTransaction class, an Ecommerce_RefundTransaction class, etc.

I envision all these classes sitting in my own dotnet assembly.

I think I need to have each of my classes inherit/extend from the
Paymentech.Transaction class only needing to change the constructor.

Here is where I'm lost (not having done this before).  How do I do this? Do
I need to do something with all the other members/methods of
Paymentech.Transaction as well?

I apologize that this question is so basic.

Terry