How to compare array to array using VBScript?

For one thing, [2w fr 5k 2j 0w] is not a valid array definition in VBScript. If you want to define an array with these 5 string elements you need to do it like this:

Array("2w", "fr", "5k", "2j", "0w")

Also, StrComp() is for comparing a string to another string. It does not support comparing a string to an array. For comparing a string to each element of an array you need a loop. How to build that loop depends on the result you want to achieve, though.

Looking at your code it seems you want to find a match in 2j2H4..., but not in w2j2H..., so simply using InStr() probably won't work for you. In that case you could use an inner loop for the comparison:

ref = Array("2w", "fr", "5k", "2j", "0w")
For i = 1 To Len(strFBString) Step 2
    For Each s In ref
        If Mid(strFBString, i, 2) = s Then
            '...
        End If
    Next
Next

But like I already said, details depend on the desired end result. If you want to check if your input string contains any of the array values you could do something like this:

ref   = Array("2w", "fr", "5k", "2j", "0w")
found = False
For i = 1 To Len(strFBString) Step 2
    For Each s In ref
        If Mid(strFBString, i, 2) = s Then
            found = True
            Exit For
        End If
    Next
Next

If on the other hand you wanted to check if your input string contains all of the reference strings you'd probably do something like this instead:

ref   = Array("2w", "fr", "5k", "2j", "0w")
For Each s In ref
    found = False
    For i = 1 To Len(strFBString) Step 2
        If Mid(strFBString, i, 2) = s Then
            found = True
            Exit For
        End If
    Next
    If Not found Then Exit For
Next

You could also use an entirely different approach, like putting your data in a dictionary:

data = CreateObject("Scripting.Dictionary")
For i = 1 To Len(strFBString) Step 2
    data(Mid(strFBString, i, 2)) = True
Next

Using that approach you could check if the data contains any of the reference values like this:

found = False
For s In Array("2w", "fr", "5k", "2j", "0w")
    If data.Exists(s) Then
        found = True
        Exit For
    End If
Next

or check if the data contains all of the reference values like this:

found = True
For s In Array("2w", "fr", "5k", "2j", "0w")
    If Not data.Exists(s) Then
        found = False
        Exit For
    End If
Next