VBA to Copy & Paste Data dependant on selection in a Data Validation List

Hi Ladies and Gentleman,
I am hoping someone here is able to give me the assistance I need. I am new to VBA in the sense that I have used quite a few Macros effectively through copying and pasting them from other threads and trying to modify to suit my situations, but I am still unfamiliar with the whole "VBA Language" itself. I am learning on the go.

My Question is: I have two worksheets.
"DETAILS" & "REFERENCES"
The "REFERENCES" sheet contains all of the information I wish to reference with future macros.
On the "DETAILS" sheet I have a column A-H merged into one. The cells in this column contain Data validation providing a drop down list of options linked back to "REFERENCES" BK:BR - (Also Merged in one column)

What I am trying to achieve
When I select from the list on the "DETAILS" sheet, I would like my macro to find the exact match on the "REFERENCES" sheet and copy all 78 cells to the right of that and paste them back next to the original list selection on "DETAILS" sheet?
Is that confusing????? Hope not.

I wonder if there is a need to clear the current contents before pasting the new cells also?

As I plan to evolve this spreadsheet over time, I think all of my formatting should be done on the "REFERENCES" sheet and copied across exactly as is.

Thanks in advance...... I'm new to this forum so I am happy to accept any advice on forum etiquette as well as VBA along the way. Your patience is appreciated.

Thanks for the reply:
This file will be shared in the sense that everyone opens up the template from a network location and saves their own individual copy to modify as required (also to a network location).
We save all of our workbooks as macro enabled and our network location is listed as a trusted site with our anti-virus software.
Hopefully that is what you are talking about. I would prefer to use a macro rather than formulas.

Once you see my workbook, feel free to ask more questions with regards to what I am trying to achieve here.

Thanks millz, this is definitely very close to what I'm after!!! On first instance it seems to work well. I need some time to tweak a few things with it but will be back to quiz you as soon as I can with some follow up Questions regarding this macro. Just a bit busy currently doing something else.

Sorry for the delay..... I have attached the latest version of my Spreadsheet.
I have made some changes and after hours of fumbling around I have given up and come running back for help.
You'll notice in my "References" Worksheet that I have added some more named ranges that I would like to refer back to with my data validation lists on the "Details" worksheet.
I was aiming to get them to work in the same fashion as shown in previous communication.
The problem is that I simply don't understand enough about macros yet to get it working.
I have attempted to tweak your existing macro and make it into 3 macros, but now they don't function when the workbook changes.
I know its something to do with the SUB name being different???