Safe internal redirect, to external - clickable link

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1

Posting a banner link on a site, I am first sending the click from my main index page to another internal page:

…/advertB/trk.htm

Note that the htaccess folder uses disallow to exclude this from indexing:

User-agent: *
Disallow: /advertB/


The advertiser wants to track when being [B]directing to[/B]: 

[http://metr.-destinsiteee.com/ABC/go/100907781/diret/05/](http://metr.destinsite.com/ABC/go/100907781/diret/05/)

a) Is it wise to send the inititial link on the home page on click to .../advertB/trk.htm  without any secondary tag, if I have one such dedicated page per advertiser? 

b) Might it be better to include the appended url from the initital link when clicking to .../advertB/trk.htm and passing this on via a redirect to their site? (recapture the url tag with GET URL VARS?)

c) What is the best way, meaning the safest for search engine reasons,  to redirect from my site to their site. And should this be done on page or thru htaccess ?

d) Also, if I add the page. ../advertB/trk.htm  to analytics, for my own tracking, will google pick up on the page for indexing when I do not want it to?
2

sorry for replying to my own post but this may change the response(s):

Since most redirects are for notifying users/search engines of moved pages,
would it be better to do a php header redirect, without any conditions?

Right on my …/advertB/trk.htm

<?php  
header("http://metr.-destinsiteee.com/ABC/go/100907781/diret/05/");?>

I’m wondering if tracking might still register.