First, for others who may read this thread, I
did overlook a feature. (I said I was a new HanDBase user

)
When you touch the Sync button on the mobile, the built-in HanDBase conduit displays a URL which may be visited by a
browser on a computer on the same wifi network. One of the options shown on that resultant web page is the ability to transfer .CSV files. So neither a Windows copy of HanDBase nor some other software is required to transfer these files. (A really nice feature, and just one of many features I probably have not yet discovered.)
CCSEB32 wrote:I purchased the Windows computer version ... started working on trying to create a form for the Note II.
A good start using the standard input form, and hopefully Dave soon will release the add-on for Android for custom forms.
this is not as easy to handle as ... I may just be too old and set in my ways to learn new tricks.
Since I am undoubtedly older than you, you are not old
enough 
as I have worked on so many different DB systems that nothing looks unfamiliar any more.
I have found that the mobile phones it references are old technology ...
The developer, Dave, has posted elsewhere that he recognizes the manuals have not kept pace with his upgrades. He has focused on improvements to the software and indicated that upgrading the manuals is on his near-term "to do" list.
I will have to figure out how to make one field (used) update to the mathematical difference between two other fields (Pres) - (Prev)
That is pretty easy. I suggest defining the field (Used) as a "Calculated" field type with result to the desired decimal places. Be sure to have the order of this field
after both of the fields the computation depends upon (Prev and Pres). My example "Configure" formula below assumes that the default value of Pres might be empty (zero), Prev is Field 4 (F4), and Pres is Field 5 (F5).
(0 Max (F5 - F4))
will need some way to make the resultant (used) value be compared to a field containing the expected upper limit (High [floating]) and another field containing the expected lower limit (Low [floating]) so that it can warn the user if the new usage goes outside of that range.
The comparison is easy, but the warning may be a bit more tricky depending upon what you want to display. I presume you will define these as two "hidden" fields (High and Low) which have been propagated by your .CSV with the appropriate float values. I would then suggest a field to warn about each condition, of field type "Conditional", which could be defined as (e.g. TooHigh):
If Field: Used
Is: Greater Than
Field: High
Output is: No Field / WARNING
Else Output is: No Field / (blank)
While there may be a way (as above I may be overlooking a feature) I cannot seem to set the No Field static text output to greater than seven characters. One could get more clever by additional hidden static text fields in order to provide a longer message, and/or additional hidden fields based on these two Conditional fields to collapse the two possible warning messages into one field. But I will leave those as an exercise for the student.
As a final note, be sure to have one or both of your two other entry fields (Tenants [integer] and (MsgCodes [text]) in order
after the Pres field, as the Used value will not be computed until you
leave the Pres to enter some other field.
Hope this gives you ideas.