ForEach Loop Container Mapping Variable From SSIS Package Not Working In SQL-Server StoredProcedure

Question

I have an SSIS package that uses a ForEach Loop Container to enumerate Excel Files in a dir. I also have a Task Flow that inserts data from those Excel files into SQL-Server.
Im trying to insert the file names into a column into the same table in SQL-Server by using a mapping variable in my StoredProcedure.
Im having trouble with my MappingVariable at the end of the script with red squigglies. The following is my StoredProcedure script.
CREATE PROCEDURE [dbo].[Insert_F_STG_v2]
-- Add the parameters for the stored procedure here
@Hrs float,
@Type nvarchar(100),
@SN nvarchar(100),
@Op nvarchar(100),
@[USER::CurrentFileName]
AS
BEGIN
SET NOCOUNT ON;
INSERT INTO [CRM_RC].[dbo].[F_StgTbl]
[Hrs],
[Type],
[SN],
[Op],
[Report_Date]
VALUES
@Hrs ,
@Type,
@SN,
@Op,
@[USER::CurrentFileName]
END
The last @[USER::CurrentFileName] in the Values block at the bottom of the script is the one giving me issues.
The following is the error:
Msg 102, Level 15, State 1, Procedure Insert_F_STG_v2, Line 95
Incorrect syntax near 'USER::CurrentFileName'.

Answer 1

This seems to be the solution, but get the following exception: 
[Derived Column [2]] Error: The "Derived Column" failed because truncation occurred, and the truncation row disposition on "Derived Column.Outputs[Derived Column Output].Columns[Derived Column 1]" specifies failure on truncation. A truncation error occurred
on the specified object of the specified component.
AND:  [SSIS.Pipeline] Error: SSIS Error Code DTS_E_PROCESSINPUTFAILED.  The ProcessInput method on component "Derived Column" (2) failed with error code 0xC020902A while processing input "Derived Column Input" (3). The identified component returned
an error from the ProcessInput method. The error is specific to the component, but the error is fatal and will cause the Data Flow task to stop running.  There may be error messages posted before this with more information about the failure.