How to concatenate the string and Parameter passed to stored procedure

Hi All,

 I am trying to bind the variable inside the stored procedure with some default string and passed parameter to SP 

but it giving error at + sign whenever i am going to concatenate it 

for example:

Structure of SP

sp_LaodData @server varchar(50)

Exec sp_LaodData '10.10.1.12'

@Var1='/FILE "\"D:\DataLoadToExcelFrom\LoadDataToExcel\LoadDataToExcel\LoadingDataToExcel.dtsx\"" /CONNECTION "\"10.10.1.64.Product.admin\"";"\"Data Source='+ @server+ ' ;Initial Catalog=Product;Provider=SQLNCLI11.1;Integrated Security=SSPI;Auto Translate=False;\"" /CONNECTION "\"Excel Connection Manager\"";"\"Provider=Microsoft.ACE.OLEDB.12.0;Data'

bold parameter i have passed but its is giving error '(Incorrect syntax near +)'

please help me for this is there any another way to concatenate 

Niraj Sevalkar