Hi

If I understood correctly, suppose you have 200 detail lines and if a user enters 50 through parameter it should print only 50 detail sections right ?

If so, use below formulas :

@inic //place this formula where you want to print sections

whileprintingrecords;
numbervar x:=x+1;

Now go in Seciton expert and select the section which you want to print and select suppress condition formula editor and give below formula

{@inic} > {?userParameterValue}