How to convert data type while using @variable function

Hi Gurus,

I have a query.

i have created a Derived Table and the statement is given below.

select 1 as SENSITIVITY_LEVEL,1 as SUBSENSITIVITY,@variable('US_T') as NITEMS, ...........

here  in @variable('US_T') "US_T" is hard coded value. I want to change to data type of hard coded value as numeric or integer

i am using sap BI 4.0 universe design tool.

Thanks in Advance.

Regards,

Jeet