How to limit characters in a .Range command?

Still refining this bit of code;

Sub renamepartsheets()
 On Error Resume Next
 Application.ScreenUpdating = 0
 Dim rs As Worksheet
 For Each rs In Sheets
     With rs
           If InStr(1, (.Name), "part", 1) Then
          .Name = .Range("B2") & "-" & Range("B5") & "cav"
          End If
    End With
 Next rs
 On Error GoTo 0
  Application.ScreenUpdating = True
End Sub

This runs great except when the total characters exceed 31 (limiting length of a tab name). My value that resides in "B2" I have found often will exceed this so I want to revise the code to only grab the first 25 characters of this cell. I have tried using the Left command but it doesn't seem to work, operator error no doubt...

Any help, as always, is greatly appreciated.