If there is a functionality that needs mod_rewrite and mod_proxy both to be on the hosting and mod_proxy is not available then would there be any way to do so without mod_proxy?

I have the following form :

Code:
<form action="/****/****" method="get" name="l***m" id="l***m" onsubmit="return redirect('l***m');" >
<input type="hidden" name="curl" value="****.com" />
<input type="hidden" name="from" value="****" />
<input type="hidden" name="sid" value="**" />
<input type="hidden" name="psv" value="*" />
<input type="text" name="****" id="****" class="inputclass" />
<input type="submit" class="b_searchcar" value="" />
</form>
Now when user enters the required information and submits the form, it gives 404 ERROR where infact it should redirect to another form. I have the htaccess ready and according to the requirement. The redirect is to a 3rd party where user has to fill in some details. It keeps giving me 404 ERROR no matter what i do.

Its hosted on BLUEHOST so i know mod_proxy does not work on that. Any ideas/solutions?

Thanks in advance.