Whilst at Credit Lyonnais, a Commercial client contacted the bank asking for some form of Electronic Payments, this was around 1986 and Direct Debits was not in the mainstream.  

I was asked if I could write a program that would read a spreadsheet containing relevant details, (e.g. SortCode, a/c number branch, and beneficiary and Amount). This file was encrypted (using my own security program)so it could not be tampered with. Why I hear you ask? Well in the mid 80's there was no real security products so I created my own.

When a disk was received by the Cash department, they simply inserted the disk and my program transmitted data to the mainframe and ultimately to BACS.  

If the code/spreadsheet had been tampered with after validation, the program would abort to ensure the disk had not been compromised..

The program was released to many of the banks' clients which saved the "cash department" a lot of time entering all the payment details manually.

Since then I have created several programs using combinations of spreadsheets using VBA and C++ and/or Java to print reports extracting the data from SQL database.