If you put your expression in a variable, this would then read:
=if($(eExp) < 0 and $(eExp) > -0.5, 0, $(eExp))
Should do the trick. I used to be concerned about performance of having an expression multiple times like that, but I have been very reliably informed (thanks, Henric Cronström) that the caching in the QlikView engine will ensure that each number is only calculated once.
No it's not rounding issue I have tried round function in a variable and then representing it in percentage so that doesn't work out because it is rounding the expression so it get the value that the expression has and its rounding that not as of the percentage. I need to calculate the percentage and then round it up