excel vba- extract text between 2 characters

Question

If i had this column:

ColA
-----
NUMBER(8,3)
NUMBER(20)

I need a VBA function that would go (note these start and end string would only ever appear once in a cell):

extract_val(cell,start_str,end_str)

ie. extract_val(A1,"(",")") and give the results:

8,3
20

I only need to use this function within other vba code not by putting it as a formula on the sheet.

UPDATE (thanks to the answer, i settled on:)

---------------------------
Public Function extract_value(str As String) As String
Dim openPos As Integer
Dim closePos As Integer
Dim midBit As String
 On Error Resume Next
openPos = InStr(str, "(")
 On Error Resume Next
closePos = InStr(str, ")")
 On Error Resume Next
midBit = mid(str, openPos + 1, closePos - openPos - 1)
If openPos <> 0 And Len(midBit) > 0 Then
extract_value = midBit
Else
extract_value = "F"
End If
End Function

Public Sub test_value()
MsgBox extract_value("NUMBER(9)")
End Sub

Answer 1

You can use instr to locate a character within the string (returning the position of '(' for example). You can then use mid to extract a substing, using the positions of '(' and ')'.

Something like (from memory):

dim str as string
dim openPos as integer
dim closePos as integer
dim midBit as string

str = "NUMBER(8,3)"
openPos = instr (str, "(")
closePos = instr (str, ")")
midBit = mid (str, openPos+1, closePos - openPos - 1)

You may want to add error checking in case those characters don't occur in the string.

Answer 2

If the string is “Value of A is [1.0234] and Value of B is [3.2345]”

If you want to extract the value of B i.e., 3.2345, then

firstDelPos = InStrRev(textline, “[“) ‘ position of start delimiter
secondDelPos = InStrRev(textline, “]”) ‘ position of end delimiter

stringBwDels = Mid(textline, firstDelPos + 1, secondDelPos – firstDelPos – 1) ‘ extract the string between two delimiters

MsgBox (stringBwDels) ‘ message shows string between two delimiters