How to convert text with middle blank space to a number in Excel?

The character that is creating the separation (originally referred to as a "space") may not be a space at all.

Try - using your mouse to select just the blank 'character' and paste it between the "" marks in the substitute formula.

or try one of these three formulas

=SUBSTITUTE(A1,CHAR(10),"")

=SUBSTITUTE(A1,CHAR(9),"")

=SUBSTITUTE(A1,CHAR(13),"")

What do they do? Those are character codes for various types of line feeds / carriage returns.

Give it a try and report back.

Since the answer was "it's not a space" - if you want to know what all the characters are in a cell, this macro will print them for you and you can compare them to their ascii values

Sub WhatIsThat()
    Dim testCell As Range
    Dim testString As String
    Dim i As Long

    Set testCell = Range("A1")
    testString = testCell.Value

    For i = 1 To Len(testString)
        Debug.Print Asc(Mid(testString, i, 1))
    Next

End Sub

Say we have a string of less than 256 characters, some of which are numbers and others are not, this should get the numbers. It does not depend on knowing which characters are non-numbers or knowing what the non-numbers are.

With the text string in cell A1:

=SUMPRODUCT(MID(0&A1,LARGE(INDEX(ISNUMBER(--MID(A1,ROW($1:$256),1))*ROW($1:$256),0),ROW($1:$256))+1,1)*10^ROW($1:$256)/10)

Some examples: