I suggest posting exactly what you have tried that fails. With URL text, the problem often comes down to getting the correct quotes into place inside the text produced by the calculation--something that can be solved either with the Quote function or by escaping quotes with the \ character where needed.
Quote ( "Apple" ) returns "Apple" (including the quotes)
"\"Apple\"" also returns "Apple"
I actually figured it out. I was using the plus sign instead of the ampersand to append text, DOH!
Here's what finally worked:
I recommend using the GetAsURLEncoded function (I think that's what its called) around your GetAsText() in case the text ever has any special characters like question marks or ampersands