Importing multiple csv files, giving them new names and extracting different columns of data to form seperate datastrings

I'm new to using Matlab and found out how to inmport data, rename it and substract different columns out of it, but I would like to know how I can properely use the loop tool to be able to extract different columns and name the datastrings for multiple files. Underneath is the code I used for one file just rewritten for all cases. It works with limited number of importing files, however with to many I run out of memory. Can somebody give me tips how to use loops to make sure the .csvfiles are imported automatically and the names of different columns of these files are are automaticaly generated and renamed either?

Thanks for the help, Rianne

Importdir=dir('*.CSV');

M1=Importdir(1).name;

M2=Importdir(2).name;

M3=Importdir(3).name;

M4=Importdir(4).name;

M5=Importdir(5).name;

M6=Importdir(6).name;

M7=Importdir(7).name;

M1=csvimport (M1);

M1_S3D_S1_D=M1(:,3);

M1_S3D_S1_UV=M1(:,4);

M1_S3D_S1_VV=M1(:,5);

M1_S3D_S1_WV=M1(:,6);

M2=csvimport (M2);

M2_S3D_S1_D=M1(:,3);

M2_S3D_S1_UV=M2(:,4);

M2_S3D_S1_VV=M2(:,5);

M2_S3D_S1_WV=M2(:,6);

%and so on

Answer 1

[Iain]

 Importdir=dir('*.CSV')
 for i = 1:numel(Importdir);
  M = Importdir(i).name;
  M =csvimport (M);
  M_D{i} = M(:,3);
  M_U{i} = M(:,4);
  M_V{i} = M(:,5);
  M_W{i} = M(:,6);
 end

If you have too many files, you'll still run out of memory...