Converting Extract to Mini-Mash

I'd like to replace some of the extract in my all extract recipes with mashed grain. How do I figure out which grain to use and what quantity of grain is equivalent. I do have beersmith, is that one of its features?

When someone says he is getting 60% efficiency with a mash of 2 lb of grain 37ppg, does that mean it is roughly equal in fermentables to 14 oz of DME 45ppg?

I did PM for over 5 years with great results. Used a 2 gallon water cooler and a vegitable steamer as a false bottom it worked awesome. Even did some 2.5 gallon AG with it, got 88% efficiency. I would use about 4 pounds of grain usually around 2 pounds base malt and 2 pounds specialty, and 1-4 pounds of light DME. I found the light DME gave me the best results both for flavor and color. Hope this helps.

Basically, 1 pound grain = .75 pound LME = .6 pound DME. You keep the specialty grains this same.

So, in this example:
6 pounds DME
1 pound crystal

you could use:

10 pounds two-row
1 pound crystal

OR

7.5 pounds LME
1 pound crystal

OR

3 pounds DME
5 pounds two-row
1 pound crystal

OR

4 pounds DME
3.5 pounds two-row
1 pound crystal

And so on. It's very easy to do, and you can make any recipe a partial mash.