Wildcard To Select All Using Numeric Field

Hi all,
I've set up a page with a gridview, and I'm trying to create a query based on three parameters and to display all records when the page loads.
I have created the first two parameters no problem, but I'm having problems with the last one.

The parameter is to be populated by a dropdownlist, where the selectedvalue is numeric.  I have done  a search and found that I can't use the '%' wildcard as it is for a string data type.
I have read somewhere that to get around this I can use the CHAR() function to convert to a character, I have tried this without success.
When creating the ControlParameter the datatype gets set to string, which I think is not working becuase the input has to be an integer for it to conver to char, am I right?
This is the query, and it is the @Application parameter that I'm having this problem with.
SELECT dbo.Issue.IssueID, dbo.Issue.ReportedBy, dbo.Issue.ShortDescription, dbo.Issue.DateReported, dbo.Issue.Status, dbo.Priority.Description AS Priority,
dbo.Application.Application
FROM dbo.Issue INNER JOIN
dbo.Priority ON dbo.Issue.Priority = dbo.Priority.PriorityCode INNER JOIN
dbo.Application ON dbo.Issue.Application = dbo.Application.ApplicationID
WHERE (dbo.Issue.Status LIKE '%' + @Status) AND (dbo.Issue.AssignedTo = @AssignedTo) AND (CHAR(dbo.Application.ApplicationID) LIKE '%' + @Application)
ORDER BY dbo.Priority.PriorityCode
Has anyone managed to do this another way?
Thanks