question about exluding "&" filter

I dont know that is this the right topic to discuss. I am newbie about xsl and using altova to write an xsl. the problem is I have to insert a link into the style sheet. the link is like that:

As u understand there is a folder.gif image which I want to give the associated link url. But altova doesnt permit to use the “&&” expression or"&" whithin the url. As i know it is used to define, for example “< less than” filter. I have to use that exact url? What might be the method?