Wow...I feel foolish...forgot to mention the language I wanted to translate that VBA code into. :)
I had a project written in F# containing other functions I use and was having a hard time with the translation of this VBA to F#...but obviously the easier thing to do is just to add a VB project to my F# solution in Visual Studio, copy the code in as is with appropriate Imports, and then reference the vb dll so that a copy is created in the F# project path and include an ExternalLibrary reference to the vb dll in the dna file. I was able to do this and have it working as expected.
Thank you for the quick response. I echo what so many have already said...your work is amazing! I only wish I had found ExcelDNA much earlier.