My problem: I would like to use Visual Basic 2005 express addition to
develop applications for Excel 2002 (version 10). The reason is that
VB.net supports more of OOP such as inheritance, etc.

In particular I would like to build a main library of classes and
functions in vb.net and call it from a simple VBA code.

I have reasonable experience with VBA (Access, Excel) and MatLab but no
experience with vb.net IDE. I am not a professional developer which
means that I don't know many things concerning "programming
environment", such as which references are necessary and when and
what additional libraries I need to download to work with particular
version of MS Office.

I was wondering if anyone could suggest where to find a step-by-step
tutorial which would tell me how to do it with Express Edition of
VB.net?
Something like" open vb.net express, make dll/com which contains a
function "f(x) = x*2", call this dll/com from VBA and use f(x)."

I have spent some time searching but I see only instructions for the
full version of Visual Studio which already includes predefined
solutions for MS Office applications.

Would appreciate your help very much!