VBA Run-time error 450 from function returning a collection - vba

Question

Context: I am writing a function which returns words/numbers present in a string which are enclosed by parenthesis.
Example: Calling ExtractParenthesis("This {should} work. But {doesnt}.") should return a collection containing two items, should and doesnt.
Error: The error I receive from the code below is
Run-time error '450': Wrong number of arguments or invalid property
assignment
It doesn't appear on a particular line and I just receive an error message with "OK" and "Help" as options.
Code:
Public Function ExtractParenthesis(strText As String) As Collection
Dim i As Long
Dim RegExp As Object
Dim Matches As Object
Dim Output As New Collection
Set Output = Nothing
Set RegExp = CreateObject("vbscript.regexp")
RegExp.Pattern = "{(.*?)}"
RegExp.Global = True
Set Matches = RegExp.Execute(strText)
For i = 0 To (Matches.count - 1)
Output.Add Matches(i).submatches(0)
Next i
Set ExtractParenthesis = Output
End Function

Answer 1

It works exactly the way you want it for me:
Option Explicit
Public Sub TestMe()
Dim myColl As New Collection
Set myColl = ExtractParenthesis("This {should} work. But {doesnt}.")
Debug.Print myColl(1)
Debug.Print myColl(2)
End Sub
Public Function ExtractParenthesis(strText As String) As Collection
Dim i As Long
Dim RegExp As Object
Dim Matches As Object
Dim Output As New Collection
Set Output = Nothing
Set RegExp = CreateObject("vbscript.regexp")
RegExp.Pattern = "{(.*?)}"
RegExp.Global = True
Set Matches = RegExp.Execute(strText)
For i = 0 To (Matches.Count - 1)
Output.Add Matches(i).submatches(0)
Next i
Set ExtractParenthesis = Output
End Function
I receive "should" and "doesnt" on the immediate window (Ctrl+G). Probably you are not aware that you are returning a collection. It should be used with the Set keyword.
To run it from the immediate window, try like this:
?ExtractParenthesis("This {should} work. But {doesnt}.")(1)
?ExtractParenthesis("This {should} work. But {doesnt}.")(2)

Answer 2

From what I understand of your comment to Vityatas answer you mean you want to run it as a worksheet function - running it directly
The changes I've made to your code will let you use it as a function:
In A1:B1 this will work: {=ExtractParenthesis("This {should} work. But {doesnt}.")}
In A1:A2 use it like this: {=TRANSPOSE(ExtractParenthesis("This {should} work. But {doesnt}."))}
NB: The curly brackets are added by Excel when you enter the formula using Ctrl+Shift+Enter rather than Enter on its own.
The one problem with the code is that you must select the correct number of cells first - if it should return three words, but you've only selected two then you'll only see the first two.
Public Function ExtractParenthesis(strText As String) As Variant
Dim i As Long
Dim RegExp As Object
Dim Matches As Object
Dim Output As Variant
Set Output = Nothing
Set RegExp = CreateObject("vbscript.regexp")
RegExp.Pattern = "{(.*?)}"
RegExp.Global = True
Set Matches = RegExp.Execute(strText)
ReDim Output(1 To Matches.Count)
For i = 1 To (Matches.Count)
Output(i) = Matches(i - 1).submatches(0)
Next i
ExtractParenthesis = Output
End Function