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).
"Over_used/Over_spent"(Losses) and "Under_used/Under_spent"(Savings) _ on a monthly basis based on data entered, the program also automatically plotted charts showing trends over a 12 month period.
Deciding What Spreadsheet Application To Use. This would ultimately be up to you. The big "fight" has always been between Lotus 1θι and Microsoft Excel. I started out with Lotus 1θι back in 1993 and learnt Lotus Macros programming(via self_tutoring). I eventually used this skill to develop _ in my free time _ various custom spreadsheet solutions(that were formally adopted for use in the departments I worked in as a brewer/manager in Guinness), before switching to Microsoft Excel in 2001. Subsequently, I developed my Excel Visual Basic spreadsheet programming skills (also via self_tutoring), because the company had chosen to adopt MS Office during the roll over to year 2000.
In addition, an Excel VB developer( who in many cases will tend to be a user turned developer, and is therefore likely to easily see things from your perspective) _ unlike a programmer _ is more likely to be positively disposed to working with you to ensure the application meets your practical needs. S/he will readily understand that the final application is meant to help solve a real problem(s), and will therefore build it to match those expectations.