Put this in a new module:
Public Function RtEqTot(ByVal Target As Excel.Range) As Double
Dim arrInput As Variant
Dim dblTot As Double
Dim intPos As Integer
Dim lngRow As Long
Dim lngCol As Long
If Target.Cells.Count > 0 Then
If Target.Cells.Count > 1 Then
arrInput = Target.Value
Else
ReDim arrInput(1 To 1, 1 To 1)
arrInput(1, 1) = Target.Value
End If
For lngRow = LBound(arrInput, 1) To UBound(arrInput, 1)
For lngCol = LBound(arrInput, 2) To UBound(arrInput, 2)
If arrInput(lngRow, lngCol) > "" Then
intPos = InStr(1, arrInput(lngRow, lngCol), "=")
If intPos > 0 Then
If IsNumeric(Mid(arrInput(lngRow, lngCol), intPos + 1)) Then
dblTot = dblTot + CDbl(Mid(arrInput(lngRow, lngCol), intPos + 1))
End If
End If
End If
Next lngCol
Next lngRow
RtEqTot = dblTot
Else
RtEqTot = CVErr(vbError)
End If
End Function