Write an addon for a program that is based on dBase, Excel, and C

A program, Campground Master, has a way to make custom coding addons to connect with other programs. I need custom implementation written to integrate with a programmable gate for entrance and exit to the campground. The gate uses a simple text file as its database.

We’d like the ability to have customer-chosen codes that integrate to their RV space account. We want to enter them directly Campground Master. We also have time-limited access (gate only works 7am-7pm), and would like to deny access if someone hasn’t paid a bill.

Also, we have staff codes that aren’t tied to a space. Staff codes work 24/7. So if you could make a field for a gate code in the user/operator database that would be good too!

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Let me know if you can do this, and what your estimate is. Thanks!