Distinguish and export data from files

I have several files as follows. .DAT and .IDX They contain data from an in-house database, created for our company a few years back, the company whom created these files for us are no longer contactable. We do not understand what format or structure the data is in within the files, all we know is the data is in the files. There are several files, the largest containing millions of records, the file size is upwards of 300mb What we require is, and we will pay well for complete completion, Either of the following scenarios A) 1) Distinguish what format the data within the files takes 2) Distinguish the structure of the data file. 3) Extract all the data from the files and put them into csv files or B) 1) Distinguish what format the data within the files takes 2) Distinguish the structure of the data file. 3) Create a .net program which reads the files and can export the retrieved data. The source code must accompany the program This is rather urgent, the continued success of our company relies on this data, to which we no longer have access, as the original software which read the data files is no longer available. We are willing to pay upto £1500 for the right solution to this problem. The main files will be made available on our web server, as they are to large to send via freelancer.com If the data is extracted to csv within 5 days then there will be a bonus of £500GBP, we will also retain your services as a priority bidder in future freelancer projects. Note: I have attached one of the smaller .idx files so you can have a look, the main dat file as I say is circa 350mb, and contains upto 40,000,000 records. Data Protection Act must be adhered to when the main file is released to the winning bidder, as the data within the files are sensitive, assurances must be given when bidding that you will comply will all UK legislation regarding The Data Protection Act, you must not copy, store or release any information within the files, all traces must be deleted after the work has finished, if you are unable to comply with this, then please do not bid.. Thank you in advance, David