Depends on what the request looks like. If you make a GET request, (one where the parameters are transmitted within the URL), you could have it first go to your script, you record it, and then issue a redirect 
use CGI; 
(store parameters etc); 
print $cgi->redirect('the.other.host/url-with-parameters');

[download]
I don't think that method will work if you have a POST method in your form.

In that case, you could accept the request in your script, record the parameters, then do a LWP::Simple request in the background, and send the results of that request to the client. Note that in that case, the other server will see ALL the requests as coming from your server's IP - which may not be what you want.

Update:Right, as b10m pointed out, LWP::Simple doesn't do POST, only get (the fact that it accepts the URL as the single parameter should have clued me in). Yes, you'd have to use LWP::UserAgent, and it's post method.

In reply to Re: Saving parameters before sending to 3rd party by matija
in thread Saving parameters before sending to 3rd party by jonnyfolk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.