Custom spreadsheet solutions which survive long after the developer has "left the scene", are often those which users accept because they discover it _ among other benefits _ makes their work quicker and easier to do. That is why the best person to develop such solutions tend to be one who works in that area, and is therefore familiar with the way the manual system operates. S/he would have an "insider's" perspective of the best way to introduce automation other users will readily adopt _ even as it solves the identified problem(s).
A person with proven competence in this area CAN become "notorious" for developing spreadsheet applications, which eliminate drudgery from the process of using MS Excel to handle large amounts of data. Typically, work that takes hours or days will suddenly take minutes or seconds to finish.
Spreadsheet Tracking As A Crucial Element For Business Development. There are ways you can use spreadsheets to record and track materials usages/stocks, product sales, and other business data such that discrepancies will be easily detected when they do occur. The use of spreadsheets when properly done, can help to uncover the cause(s) of "losses" in virtually any aspect of a business operation.
The savings _ from using your "in house" expertise _ in terms of money and man_hours alone, will quickly justify the investment you make in "developing the needed skills" _ especially, when you compare what you spend with the cost of purchasing a commercial software application _ or even engaging the services of an Excel VB developer.