DLL example required

Kind folks,

Has anyone got an example (snippet) of getting a column of values (reals)
from Excel into a Delphi (v4) DLL, doing something with them, and then
getting the results back into Excel.

I'm happy with creating and using a DLL with simple values, even a pop-up
form, but seem to have lost it when it comes to vectors and arrays.

Thanks in anticipation!