Client database with calculation program

Database to enter and store all client details, and locate and retreive them. Will be accessed by multiple users over the internet. Part of database will have a section for data entry and these figures entered will need to be computed and calculations achieved. Similar to the workings on an excel spreadsheet (eg. =A6*B4) An example is, we will obtain a clients phone bill, enter in all call details. These calls then need to be matched against other phone companies call rates and calculated, so we can see which phone company is the cheapest. Web based application preferably using MySql and PHP. Coder must be experienced on RAC, completing at least 30 jobs, possess good English skills and? not be working on many (or any) other projects, so they will be able to complete in the required timeframe. ## Deliverables Please see attached files for further explanation and examples Basically I want a database that will be hosted on an external? server and my staff will log in over the internet and are able to view or change things. Staff will each need unique logins to access the database and their activity and any changes they make should be noted as being done under their ID. Different staff will have different access levels and restrictions on what they can do and what they can view. More information in attachments. Please make sure you understand all requirements before bidding. If there is anything you want clarified or want to suggest something, please send a question and I will answer.