I don't think you can measure your efficiency without powdering some malt and mashing it. Any other method of defining your baseline (theoretical 100%) is just an estimate.
Yes beersmith figures efficiency for any wort derived from malt. You have to fill in the grain you used and how much, then enter what your finished batch size and gravity was.
Get to the view where you would edit a recipe and push the button labeled "Brewhouse Efficiency" next to the box where you entered your efficiency estimate, just to the right of the boil time. It will open a dialog where you fill in the numbers.
Sounds like a case of PEBKAC (Problem Exists Between Keyboard And Chair).
I found BeerSmith to be difficult to use, but I had no difficulty in figuring efficiency with it.
ProMash automatically figures it. It looks at your recipe, where you created it... then your gravity reading from your hydrometer and the volume. You input the OG and the volume for the batch and it spits it out at you, because it is already looking at your grain bill, potential points, volume etc... everything is linked together. So, all you do is tell it your ACTUAL OG and your ACTUAL volume and it already knows the rest.
In beersmith, just click brewhouse efficiency and enter your OG.
The brewhouse efficiency is then calculated from your recipe and batch volume.
It's easy.