web_reg_save_param_regexp problem

Hi

I am not very good with regular expressions, and I am strugling now with this problem. I need to catch the value of the parameter "lt", that is send by the server when you go to the first page of a web application. It is send like this:

type="hidden" name="lt" value="LT-zzzzzxxxx1242476287698ourwebsite.com/>

So I want to use a web_reg_save_param_regexp to catch it. But no matter how I try to write it, it doesn't seem to work. The code below is accepted by LR, but gives the eror that no value is found for it...so I am doing something wrong,  Can anybody see the problem?

web_reg_save_param_regexp(
"ParamName=requestId_2",
"RegExp=type=\"hidden\"\\ name=\"lt\" \\ value=\"(.*?)\"",
SEARCH_FILTERS,
"Scope=Body",
"IgnoreRedirections=Yes",
LAST);