input double(YBIRTH SEX CLINICALVAR) float(age CONDITION Group)
2002 1 5 18 1 1
2002 2 5 18 1 1
2002 1 5 18 1 1
2002 1 4 18 1 1
2002 1 2 18 2 1
2003 1 4 17 1 1
2002 1 5 18 0 1
2002 2 5 18 0 1
2002 1 2 18 1 1
2003 2 5 17 1 1
2002 1 1 18 2 1
2002 1 2 18 2 1
2003 2 1 17 0 1
2002 2 3 18 2 1
2003 1 2 17 2 1
2003 1 5 17 0 1
2003 2 5 17 1 1
2003 1 5 17 1 1
2002 1 5 18 0 1
2003 2 5 17 0 2
2003 1 5 17 1 2
2003 2 4 17 1 2
2002 1 1 18 1 2
2003 1 2 17 0 2
2002 2 2 18 2 2
2003 1 4 17 1 2
2003 2 2 17 2 2
2004 1 5 16 0 2
2003 1 5 17 1 2

To explain my dataset, I have 6 variables, year of birth, sex, clinical variable, age, condition and group. How do I split the dataset by group i.e. 1 or 2 so that I can then determine what impact each group has on the other variables? i.e. how group 1 or 2 is different depending on a person's age, sex, clinical history, condition etc. please? Also, if i wish to conduct a regression analysis to determine how much each variable in each group is predicted by ownership to group 1 or 2 am i best to do this before I split the dataset (if I can)? Many thanks for your help in advance, I'm used to SPSS so I hope I explained myself clearly.