Again, Excel would not become your "database", it would become your reporting tool. In other words, the program to show manager the sales results. The TCS system is your database; it actually collects and stores the sales data (i.e. it is a database). However, do I understand correctly, that the data in the text file is not in a list form? For Example:
Customer
Sales
Profit
A
100.00
10.00
B
150.00
20.50
etc. First, again I recommend downloading Visual Studio, and challenging your VB and SQL skills. If the data in the text file needs to be ordered into a database first, so you can query the data, before showing it in Excel, I recommend using Visual Studio's built-in Database program to first store your data. So: The TCS System creates a text file (with "chaotic" data) --> your application reads the text file, extracts the necessary data, and puts it in order. Then it stores the ordered data in MS SQL Express Server (database program) --> next your application queries the database, and writes the necessary data (for example Q1 sales) to an Excel file. And you create a macro that builds the pivot tables from the data. As an alternative, you could use a regular version of MS SQL Server, installed on a server, and create queries directly in Excel from any workstation.
My advice is free, and you may get what you paid for.