Yahoo Pipes - Having Issues! Need some help.

Hey I can't seem to figure this one out. Maybe you guys can help me.

How do I join or append an rss url to an already existing url so the resulting rss feed like this: MysiteTheirsite

Example

My site url looks like this: "www.mysite.com/load.php?="

Their site (which pumps out the rss feed) outputs a ton of this:

"hxxp://www.theirsite.com/bunch-of-text"

"hxxp://www.theirsite.com/more-bunch-of-text"
etc.

So how do I get yahoo pipes to put my site "www.mysite.com/load.php?=" in front of their urls per each rss update and then output a new rss feed? What operators need to be used for doing this?

I'm trying to get the end result to look like this:

"hxxp://www.mysite.com/load.php?= hxxp://www.theirsite.com/bunch-of-text"

"hxxp://www.mysite.com/load.php?= hxxp://www.theirsite.com/more-bunch-of-text" (no spaces)

See? Both sites are now joined, ready for twitterfeed to tweet out the new links on autopilot. How do you do this in yahoo pipes?

anyone know?