IUIAutomation::CreatePropertyConditionEx で第3引数に PropertyConditionFlags_MatchSubstring を指定することで部分一致条件での検索が実施されます。

Sub Excelをタイトルに含むChromeブラウザを取得する()
  Dim uia As CUIAutomation8: Set uia = New CUIAutomation8
  Dim root As IUIAutomationElement: Set root = uia.GetRootElement
  ' Chromeのウィンドウを探す
  Dim cnd1 As IUIAutomationCondition: Set cnd1 = uia.CreatePropertyCondition(UIA_ClassNamePropertyId, 
  "Chrome_WidgetWin_1")
  ' CreatePropertyConditionExの第3引数にPropertyConditionFlags_MatchSubstringを指定すると部分一致で検索できる
  Dim cnd2 As IUIAutomationCondition: Set cnd2 = uia.CreatePropertyConditionEx(UIA_NamePropertyId, "Excel", PropertyConditionFlags_MatchSubstring)
  Dim cnd As IUIAutomationAndCondition: Set cnd = uia.CreateAndCondition(cnd1, cnd2)
  Dim ary As IUIAutomationElementArray: Set ary = root.FindAll(TreeScope_Children, cnd)

  Dim i As Long, elm As IUIAutomationElement
  For i = 0 To ary.Length - 1
    Set elm = ary.GetElement(i)
    ' ウィンドウのクラス名と名前を出力
    Debug.Print elm.CurrentClassName, elm.CurrentName
  Next
End Sub