So I am working on an Excel Project that is going to load a C++ dll using VBA. What I'd like to do is to be able to pass an Excel range with no specific type (data can be numerical or categorical) to the C++ dll (The best way I can describe my Excel range is of the type variant).
So the steps probably involve:
- Load the dll in VBA
- Send the excel range to dll (The range may contain columns of numbers and/or columns of strings)
- manipulate the data from excel in the dll file
I am thinking of using excel variant and C++ variant. But it's not clear for me how to use the C++ variant as I couldn't find any good documentations on it.
Another suggestion I received was to ues COM programming.
My Questions:
- Could a kind soul possibly provide pointers for me on how to proceed? (e.g. by providing the C++ prototype, and a simple example of how to handle the variant)
- Does anyone know any good documentation/tutorial on using C++ Variants (and perhaps jointly with VBA)?
- Is using COMs preferable to using VARIANTS if speed is an issue?
- Is using the C API an option?
UPDATE:
- The size of the ranges I need to manipulate can be large (~ 500,000 rows).
- Speed is a factor, thus, I'd like to avoid unnecessary copying as much as possible.