Call on a Web Service to populate a Crystal Report with C#?

[crazyduke]

I am using Microsoft Visual Studio 2005 to build a project in C# that utilizes some Crystal Reports that are populated via DataSets. Code will generate a PL/SQL statement which gets passed to a web service which gets the XML and populates the dataset. This all works fine but my concern is parameters. I can set parameters at the report level but I am working with large amounts of data to be pulling across a web service. I want to retrieve specific XML to improve performance. The web service utilizes an Oracle database. I was thinking of maybe trying to use bind variables but I can't figure out how to do this via web services. My web service will only accept a string as a parameter and like I stated I have been passing in a PL/SQL statement. Just thought someone may have some experience with crystal, xml, and web services. It's all new to me. Any direction would be greatly appreciated.