Searching for String inside another (with interruptions), on Excel - vba

Question

I'm trying to check whether the main string contains the entire substring, even if there are interruptions.
For example:
main string = 12ab34cd,
substring = 1234d
should return a positive, since 1234d is entirely contained in my main string, even though there are extra characters.
Since InStr doesn't take wildcards, I wrote my own VBA using the mid function, which works well if there are extra characters at the start/end, but not with extra characters in the middle.
In the above example, the function I wrote
works if the main string is ab1234dc,
but not if it's 12ab34cd.
Is there a way to accomplish what I'm trying to do using VBA?

Answer 1

Note Both of the methods below are case sensitive. To make them case insensitive, you can either use Ucase (or Lcase) to create phrases with the same case, or you can prefix the routine with the Option Compare Text statement.
Although this can be done with regular expressions, here's a method using Mid and Instr
Option Explicit
Function ssFind(findStr, mainStr) As Boolean
Dim I As Long, J As Long
I = 1: J = 1
Do Until I > Len(findStr)
J = InStr(J, mainStr, Mid(findStr, I, 1))
If J = 0 Then
ssFind = False
Exit Function
End If
I = I + 1: J = J + 1
Loop
ssFind = True
End Function
Actually, you can shorten the code further using Like:
Option Explicit
Function ssFind(findStr, mainStr) As Boolean
Dim I As Long
Dim S As String
For I = 1 To Len(findStr)
S = S & "*" & Mid(findStr, I, 1)
Next I
S = S & "*"
ssFind = mainStr Like S
End Function

Answer 2

Assuming you have 3 columns "SUBSTR","MAIN" and "CHECK" and your "Substring" data range is named "SUBSTR"
Sub check_char()
Dim c As Range
For Each c In Range("SUBSTR")
a = 1
test = ""
For i = 1 To Len(c.Offset(0, 1))
If Mid(c.Offset(0, 1), i, 1) = Mid(c, a, 1) Then
test = test & Mid(c.Offset(0, 1), i, 1)
a = a + 1
End If
Next i
If test = c Then
c.Offset(0, 2) = "MATCH"
Else
c.Offset(0, 2) = "NO MATCH"
End If
Next
End Sub