Executing stored procedure with input parameters using sp_executesql

Stored procedure name proc1
Parameters are @param1, @param2, @param3
Values are 1,2,3

declare @SqlString nvarchar(2000)
declare @ParamDef nvarchar(2000)
set @SqlString = N'exec proc1 @param1, @param2, @param3'
set @ParamDef = N'@param1 bit, @param2 bit, @param3 bit'

EXECUTE sp_executesql @SqlString ,@ParamDef, @param1 = 0, @param2 = 1, @param3 = 1