SAS data decile making



I am using SAS and trying to make descriptive statistics. I started using it few months back and can do simple analysis but this is tough for me. I am sure someone can help me with this. Thanks in advance. THe variables i have are following; Firm, Year, Month, VDecile, A, B, C, Each month all the Firms are divided into decile portfolio based on VDecile variables at time t=month. IN each decile based on Vdecile(variable name) i want to compute cross-sectional median of A,B,C at t+1 (month+1). Next i want to compute time series mean of these median portfolios.
Thank you very much