Spreadsheet feature: select cells with formulas, turn it into a function?

I have a steadily-expanding spreadsheet for doing thermal mass calculations. Various areas of the spreadsheet calculate different things (volumes of wall segments, etc). I’d like to reuse these areas by ‘calling’ them from other parts of the spreadsheet. In other words, I’d like to use them as functions.

Of course, there’s the option of programming the functions in the spreadsheet’s BASIC, but it occurred to me to wonder whether there’s an easier way.

Can one part of a spreadsheet ‘call’ another without writing a separate program? Or alternatively, is there a way to ‘capture’ the internal logic of an area of the spreadsheet and turn it into a function?

I’m using NeoOffice on the Mac. If it turns out that another spreadsheet, such as Microsoft Excel, can do this, it would be a serious push towards buying that spreadsheet. If Apple’s Numbers does this, I’ll be really embarassed, because I already have that.

I’m not sure if this can be done in Excel, but then I’m not 100% sure exactly what you’re intending to do. Do you have an example of what you mean by a function in this instance? Usually the term “function” in Excel is simply used to mean any mathematical or other operation with the form =sum(a1:a7) or the like.

Well, I use “formula” to describe the calculations embedded in cells, such as =SUM(a1:a7). I use “function” do describe the programmed operations that formulas can use: “the SUM() function”.

I am aware that I can write new functions using the spreadsheet’s builtin BASIC; I was just hoping that there was a way I could use the formulas already embedded in the spreadsheet rather than having to write them all over again as functions in the form of BASIC programs. For example, if there was a command to ‘push’ values to specified cells, then recalculate, then read values from other cells…