Try this..
Select the Object in Universe. Go to its properties.
Edit LOVs now you have DESKi kind of Window there. In filter pane drag and drop that object and add Condition GREATER THEN AND ADD CONSTANT 10000.Save and Close.
Now, Export the Universe with LOVs.
Now try to use the Same Object in Webi prompt. If you give Prompt then it won't give values less then 10K.
and if you allow user to enter any value they like ...in this case if they choose less then 10K webi will throw Exceptions...and will endup with error which will never say that what is the Cause.
So give it a hit and train your Users.
Thanks,
Ab