I don't know, as I no longer use the Crystal parameter page. Which is my solution to your issue...build your own parameter input screens and then you don't have the limits that Crystal imposes.
There are some drawbacks though. 1) I am assuming that you are getting your data via a stored proc or pushing from a app. 2) you can't use the IN function for your parameters.
Hopefully this can guide you to a solution that works for you. If you are stuck using the Crystal parameters, then obviously my solution won't work.
On another note...over 1000 selections, what a tedious report to run those must be.