Desktop Application that connects to Remote Database

The purpose of this project is to design and create an application for the financial accounting workers of a Small Business to interact with the already existing remote database. It includes the development of a desktop application in C#, the webservice(s) for the server and a secure communication channel. Currently, the financial accounting information of the company is done on spreadsheet software. However, the company (a small business located in Brazil) does have a private cloud system used for sales, purchases, inventory and reporting activities. The system was designed and created by one of the owners, who are not from an IT background. Data from sales and purchase orders that exist on the private cloud system are retyped on the spreadsheet, on a daily basis. A total redesign is being made, to include lacking functionality. One of the desires is to integrate the financial function of the company (2 frequent users today) with the rest of the private cloud, by means of the Application this freelance project hopes to originate. The application has been described as a mostly CRUD desktop windows forms software that connects to a remote database over an ssl channel, and functions pretty much like Excel, but with dropdowns instead of allowing users to freely type on cells. Important: Ideally, it would be something similar to GNUCash, with probably less functionality and integrated to the current system.