Good afternoon RobynC

Does this work OK for you - it will work on the value contained in cell A1, no clue as to where you're getting you're string from, but just adapt it to suit :
Sub test()
Set a = Range("A1")
b = Mid(a, 5, Application.WorksheetFunction.Find("_", a, 5) - 5)
MsgBox b
End Sub
HTH

DominicB