(and if anyone says "use a calculated field in a query, I'm going to stab myself in the jugular with a butter knife! I don't know what the f*&k that means!). Thanks
Okay, having read this thread over a few times, what I think you meant by that doesn't have anything to do with people saying "it's a bad idea to store calculated values in tables", I think you may have meant something more like, "Don't just tell me to use a calculated field in a query, be more specific, as I don't know what that means in my case".
Really I have no idea - just my guess as to your intention there. Feel free to tell me it was something totally different.
Either way, the two potential meanings are, as others have mentioned, related. In Access databases, with relatively "small data", it's usually better to perform calculated values at query run time - forming whatever expression at that point that you need to, rather than materializing that in a table. But, sometimes even in Access, and many times in other environments, it's not a bad idea.
Brief summary of the 2 sides here
But to answer your question. How to take a control value from a form, and get it into a table, where the control isn't bound to a RecordSource field, but rather contains an expression/calculation? You would include the field TotalMinutes in the form's RecordSource, and drag it onto the Form as a bound control. Then, you might add code in the form's BeforeUpdate event, and assign the value: Me.ControlNameOfTotalMinutes.Value=ControlNameOfCalculation.Value