Filter one list creating possible combinations

Job ID: 36488055

Budget: $30 – $250 USD

Here are the steps of this very simple project.
1. We are going to provide you a list of the radio and tv stations call letters (all are 4 letters in length) in a specific country. As an example: WABC
2. Each of these stations starts with the letter W and then followed by 3 random letters. Example from above: WABC (where the W will always be the constant in every set of call letters).
3. Your job will be to create an export, in csv format, of the possible combination that DO NOT show up on the supplied original csv file that we provide. Example from above: WABC could also be WACB, WBAC, WBCA, WCBA and WCAB.
4. The next thing you would do is compare all of those combinations against the original csv file and if they exist remove them from the final csv file. Basically, we are looking for what 4 letter combinations remain after checking the nearly 10,000 records in the original file.
5. The last objective of this process is to also, in that same file, generate what combinations were never used. For example, if WZFD does not show in the original csv file you would run the scenario on that set of letters as well and add them to the csv.

Ultimately, it is going to generate thousands of combinations and that's what we want to figure out, but NONE of the combinations on the final csv file should exist on the original csv file.

In the end, a web page we can upload this csv file and output the generated file would be great. We are looking to stay under $100 for this project please.