Not sure if I really have the subject proper or not. This is what I want to
do.

We have a spreadsheet that we keep individual workers times on. Every day,
we have to take their time sheet and figure the amount of time worked, then
enter it into the sheet. The times are truncated to the nearest 10th of a
minute.
IOW, 11:12 is 11.2 but so is 11:13 thru 11:17.

What I'd like to do is on a control key sequence, pop up a box to enter the
starting and ending time, then when <OK is pressed or clicked, or when you
hit enter, have it calculate the time to the tenth, and insert it in
whatever field the cursor is in at that point.

Any help???

Thanks!!
Shawn