MATLAB and Mathematica help

jemma

Hi all,
In Mathematica I have used the NSolve function to give me all the possible values of a1, a2 and a3, given the parameters I have set for the equations, for example:

NSolve[{an1 == a1, an2 == a2, an3 == a3, an4 == a4} /. params, {a1, a2, a3}]

Is it possible to do this in MATLAB to find the different values of a1, a2 and a3?

Also, in MATLAB I have a While loop saved as a funtion m-file which is used in another m-file within a For loop that includes a count i=1:1000. I want to do this in Mathematica so that:
For i=1:1000,
(then my while loop function)
If (conditions), count = count+1
End.
How do I do this in Mathematica?
Thanks!