Merging Table Cells with Text under Certain Conditions

Hi Everyone,
I hope I'm posting this in the right section of this forum.
Have been using Excel Spreadsheets with simple formulas in a while at work but now I was going to use Excel in a way I do not know how to get it
working for me. I have no clue about VB Scripts or Makros in general or creating formulas with LookUp or Check if a cell value if True or False (Cell is
filled or empty).

Here is what I need and I hope someone in this forum can help me out.

From a supplier I will get a spreadsheet including the the following Information which I need to convert into an url including trailing slash (/) for an online store.

Column A = Value of Main Cartegory (e.g. Holidays)
Column B = Value of Subcategory_1 (e.g. Christmas Decor)
Column C = Value of Subcategory_2 (e.g. Candle Holders)

Those raw data are without any trailing slashes.
Now I want to create a column e.g. Column D (product_url) which should be a summary of column A thru C but if there is only a Value for Main Category
there should be no trailing slash,
if there is a Value for Main Category and a Value for Subcategory_1: no trailing slash after Subcategory_1 but trailing slash between Main Category and Subcategory_1.

The result should look like this:
Holidays (Main category)
Holidays/Christmas Decor (Main category & Subcategory_1)
Holidays/Christmas Decor/Candleholders (Main category & Subcategory_1 & Subcategory_2)

Is it possible to create something like that in Excel at all since all values will only be text and the trailing slash is actually functional for Excel calculations but in this case it would have to be treated as "text".

Any help will be greatly appreciated since I am talking about more than 3500 products (and increasing) I will have to create the right url's for.
Thank You
verdecove