I'd like to model 9m long column(to make code check slenderness) and my story levels are at 0.00 +4.50 and +9.00. So program cuts my 9m column into 2 parts.
Use a unbraced length modifier of 2 on the columns, assuming it is unbraced in both directions. What it will do is multiply 4.5 m * 2 = 9 m to get to your true unbraced length. This is in case the program does not automatically pick this up in the design post-processor.
there is another way to make your top story as master and then column will display in full height. One of my collegue did this. I will double check it for you tomorrow.