This is difficult. In normal a game, I would have played b4, but after dxc5, it is more or less equal.
Interesting position
Nbd6 is the best move i can think of.. then black has to play dxc4. Then Qf3 is the next move for white after black plays dxc4
Good try panadh,a high rated player also went for b4...but they are not best moves...even Nbd6...white can get to better position...just apply ur mind from all prospective...don't neglect kings side..even i was not able to do that..it is a lovely position to keep mind thinking...keep trying ,this postion was sent By a GM to me..i am in touch with him through mails..GM IGOR SMIROV...i will post the answer in few days...until then keep trying
Even I can c only b4
1st line:b4-d*c5,Nd6-Bc7,N*c4-Qe7,B*c7-Q*c7,Ncd6-Na6 or Be6,0-0 followed by Qd4
2nd line:b4-d*e4,B*f7-K*f7,Nd6+-Kg6,b*a5-Q*a5,Qd4-Qd5,Qe3-Qd3,N*e4(+=)
3rd line:b4-c*b5,B*d5-Bc7,Qh5-g6,B*c7-Q*c7,Qh6-Qe5,a*b5(+-)
But advantage in 2 moves?:(U gotta tel how!
Its not about advantage,its position improvement ....b4 is not right move..
. i will post the answer tonight...keep trying
black's king seems to be cornered in a very weird manner..
haven't looked much into the position..
Qd4 Bh6 could threaten the black king.
(waiting for the answer) 
Oh sorry,i had forgotten that
This was problem sent by GM Igor Smirnov and he added saying that many GM's were not able to solve it..so no worries if u couldn't figure it..
Let’s look again at the starting position of this example. 3 white’s pieces are under an attack. So your first impulse is to retreat or to do something else about it. However it is your emotional impulse. If you stay calm and confident, you will realize that there is no danger here actually.
That’s why white should simply make castling 1.0-0!
After 1…cb 2.Bd5 white is dominating.
1…dc 2.Nbd6 gives white very active position also.
1…de 2.Nd6 is totally bad for black.
The position is so bad for black, 0-0 is definitely not the only winning move.. no wonder white won without playing it. I still cant see why other moves are inferior to 0-0. except b4, every other move suggested by the members here should win.
Though white won the game in the end, but he didn't make his best decision here.White to play..Suggest Next 2 moves for white where in he can get position advantage ...This is tough one xx
Thank you.
Best Regards
Shruthi.Desai