You could use search to find numbers then expand to the word and use RegEx to see of the word has letters e.g. the following will find all the examples in this thread if they are in the main document text range
Code:
Sub Macro1()
Dim oRng As Range, oNum As Range
Set oRng = ActiveDocument.Range
With oRng.Find
Do While .Execute(findText:="[0-9]{1,}", MatchWildcards:=True)
Set oNum = oRng.Words(1)
If TestRegExp("[A-Z]", oNum.Text) = True Then
oNum.HighlightColorIndex = wdYellow
End If
oRng.Collapse 0
Loop
End With
End Sub
Function TestRegExp(strFind As String, strText As String) As Boolean
Dim objRegExp As Object
Dim objMatch As Object
Dim colMatches As Object
Set objRegExp = CreateObject("VBScript.RegExp")
objRegExp.Pattern = strFind
objRegExp.IgnoreCase = True
objRegExp.Global = True
If (objRegExp.Test(strText) = True) Then
Set colMatches = objRegExp.Execute(strText)
For Each objMatch In colMatches
TestRegExp = True
Exit For
Next
End If
Set objRegExp = Nothing
Set colMatches = Nothing
Set objMatch = Nothing
End Function