Yes, you can drop the parameter on to the report.  If is a date range, I create two formulas, one for the beginning date, the other for the ending date: minimum({?Date Range}), maximum({?Date Range}).  If it is a multivalued parameter, you can use the join function.  I think the format is join({?parameter},", ").  That will show the values separated by commas.

When you say you cannot get it to work, what do you mean?  Of course I am assuming that the {?parameter} is a string parameter.  If not then you may need to put in the totext function, example: totext({?Parameter}).

Ok, parameters come in different varieties (numeric, date, string, etc.), basically it determines what kind of data you want to filter on (normally what a parameter is for).

In using the join function, it wants a string as one of the arguments. If the parameter you are trying to display is numeric, then the join function will generate an error.  Where as you can use the totext function to convert a number (or date, etc.) to a string.  Crystal Reports (and the web) have good resources describing how to use join and totext.

I hope this helps.