Hi, I have a similar problem but in my case I use the same parameter at three different places in my Query. If I specify a parameter name, I get this error when trying to run the report:
"The Value expression for the text box 'Param' refers to the field 'Param'/ Report item expression can only refer to fields within the current dataset scope or, if inside an aggregate, the specified dataset scope. Letter in the names of fields must use the correct case".
If I only put three "?" mark, it creates automatically three parameters but at least the report works (but I need to copy the parameter value in three different input boxes)
I also have to specify that im using SSRS 2008R2 and ODBC (Progress 9.1D)
UPDATE: ok, I managed to do it by only putting "?" mark for all parameters and setting the default value (=parameter1) and visibility (hidden) for parameter2 and parameter3.
My next question is how to set up wildcard character for "BEGINS WITH" parameter? My report works only if I put the '%' symbol at the end of the input box value (ex: RB%). When I try to put the '%' in the query itself (because I dont want the user to type the wildcard) it doesnt seem to like it.