I can’t find how to pass a range to my “MyFirstValue” function.
I’ll give you a very simple example to explain.
In the cell:
“=MyFirstValue(A1:B20)”
In the function:
Function MyFirstValue(rng As Object) As string
oCell = rng.getCellByPosition(0, 0)
MyFirstValue = “MyFirstValue=” & oCell.Value
End Function
When I call the function I get this error message:
BASIC runtime error.
Object variable not set.
You can not pass a range as an Object to a custom function. You can pass the numerical and textual values of the range as a two dimensional array.
Thank you so much truly.
ChatGPT only gave me wrong directions and led me astray.
I wasted two days looking for solutions online.
It’s actually the most logical thing but it didn’t come to mind.
Thanks so much again.
what prompt did you try ?
I can’t believe it… A programmer (even if he is a beginner) ask the ChatGPT: how to write LO macros…
Why?!?!?!
cause the “documentation” is messy, redundant, often outdated, not well indexed,
the API itself not so clear,
the IDE a pain (for Basic),
the execution not so stable
etc etc … 
may be …?!
but Chatgpt was »trained« with exactly this data, in what way should this stochastic parrot provide better answers?
maybe speed over Monte Carlo method - Wikipedia
or just Placebo - Wikipedia 
interesting prism to evaluate the answers in this very site either 
… if you don’t use VBASupport 1.
Try this function:
Option VbaSupport 1
Function TestFunc(arg)
Dim oRange, typeArg As String, v, val
typeArg=TypeName(arg)
If typearg="Range" Then
Set v=arg
Set oRange=v.CellRange
val=oRange.AbsoluteName
ElseIf typearg="Variant()" Then
val="(" & Lbound(arg, 1) & " to " & Ubound(arg, 1) & ", " & _
Lbound(arg, 2) & " to " & Ubound(arg, 2) & ")"
Else
val=arg
End If
TestFunc=typeArg & ": " & val
End Function
Then
=TESTFUNC(A1)
=TESTFUNC(A2:D7)
=TESTFUNC(12554)
=TESTFUNC("ABC")
=TESTFUNC({1;2;3})
… but be cautious. In a module using Option VBAsupport 1 some Basic commands work differently also in user code not explicitly relying on VBA support. (I don’t know an index of the cases.)
There is another non-obvious point.
If we pass a cell array containing formulas to a user-defined function as an argument in VBASupport 1 mode, then when analyzing the argument cells we may encounter “dirty” cell values.
IMHO …the most stupid case:
'try with|without »Option VBAsupport 1«
print (rgb(255,100,60))