T-SQL检查文件是否存在

Am trying to check whether a file exists, and store the result in a variable. Am expecting the variable @file_exists to be either true or false, but am getting the error:

将nvarchar值'xp_fileexist C:\ ABC \ myfile_20200521.xls'转换为数据类型int时转换失败

这是怎么回事?

DECLARE @filepath VARCHAR(MAX), 
        @file_exists INT = 0, 
        @sql VARCHAR(MAX);

SET @filepath = (SELECT CONCAT('C:\ABC\myfile_',convert(varchar,getdate(),112),'.xls'));

SET @sql = N'xp_fileexist '+@filepath+ N', '+@file_exists+ N' OUT' 
EXEC sp_executesql @sql

IF(@file_exists = 1)
    PRINT 'File exists'