hawkeyeboy, this is an excellent suggestion only if you are using the aggregate function MAX withing a grouping query. However, Drahos is looking to emulate the MAX function as structured in Excel. The following should do the trick:
Create a new Module and save it as modMax.
Copy and paste the following text into the module:
Public Function MAX(ParamArray Number()) As Double
Dim x As Double
For x = 0 To UBound(Number)
If MAX < Number(x) Then MAX = Number(x)
Save the module with these changes.
To use the function, do exactly as with excel. For example: ?MAX(1,7,5,4,19,13)
...should return 19.