Access 2010 Code for If Member of Group Using Field in a Table

I have an Access 2010 database and a command button with the following code:

  Dim stDocName As String
  Dim stLinkCriteria As String
  Dim strFindEval As String
  Dim strFindStaff As String
  Dim Staff As String
  Dim Evaluator As String
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
Dim UserName As String
    UserName = Environ("USERNAME")
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
    If UserName = "ABC" Or UserName = "DEF" Then
    strFindEval = InputBox("Enter Evaluator's Initials", Evaluator)
    strFindStaff = InputBox("Enter Staff Member's Initials", "Staff Member")
        stLinkCriteria = "[Staff]=" & "'" & strFindStaff & "'" _
        & " AND " _
        & "[Evaluator]=" & "'" & strFindEval & "'"
            GoTo Select_Form
        End If
    strFindEval = UserName
    strFindStaff = InputBox("Enter Staff Member's Initials")
        stLinkCriteria = "[Staff]=" & "'" & strFindStaff & "'" _
        & " AND " _
        & "[Evaluator]=" & "'" & strFindEval & "'"

Select_Form:
' Accounting
    If strFindStaff = "GAS" Or strFindStaff = "RJL" Then
        stDocName = "frmEvalStaffAcctDone"
            Else
        stDocName = "frmEvalStaffDone"
    End If


I need the code to use the data entered in the strFindStaff prompt and then see if this user is a member of the ACCOUNTING group.

I'm hoping to replace the following so that it looks to see if "GAS" OR "RJL" are members of a group (in this example ACCOUNTING).

' Accounting
    If strFindStaff = "GAS" Or strFindStaff = "RJL" Then
        stDocName = "frmEvalStaffAcctDone"
            Else
        stDocName = "frmEvalStaffDone"
    End If


The table name is STAFF and the group field is named GROUP.

Note I have code from a 7/11/2013 post on Experts Exchange labeled "Access 2010 Code for If Member of Group", but I couldn't get it working for this project.

Thanks in advance!