If you NEED to do this in SSIS, I think you are going to need a for each loop (or similar).
If you can do this on the TSQL side before or as you pull it into SSIS, that may be easier, but this assumes that the variable names are either coming from SQL OR can be hard-coded into a temp table. Here is a quick and dirty example:
WITH cte AS (SELECT 'hello' AS data, 'world' AS data2 UNION SELECT 'world', 'hello')
SELECT DISTINCT REPLACE(SUBSTRING((SELECT ',' + data + '=' + data2 AS [text()] FROM cte FOR XML PATH('')),2,1000),',','&') FROM cte
Here I am using "data" as the variable name and data2 as the value and I get "hello=world&world=hello" as my result.