Some years ago I bought, "Accounting for Lotus 123" in a Manila bookstore. The book was written for the DOS version of Lotus 123, with multiple files. I rewrote the program provided to work as an Excel workbook, with each file within one worksheet. All worksheets were correctly linked to work as one complete workbook.
Most Lotus formulas are quickly and easily converted, but I do remember that one formula caused me to specifically research for the solution, which was quickly found.
I can easily prepare Excel worksheets providing complete requirements are made available to me.
Regards...George A Warriner