Apache 2.4 strip query parameter and add that as a header - apache

Question

I have the following url -
http://ip:8080/dashboard/db/testdash?id=add&t1=abc
I want to strip off t1 from the url and add that as a header to my proxy request. I have working reverse proxy conf and I want to intercept this url strip the t1 parameter and add that as header which will be sent to the destination
I have the following configuration for my virtual host listening on 8080
RewriteEngine On
RewriteCond %{QUERY_STRING} ^(.*)t1=(.*)
>>>Need to add the rewrite logic here
>>>Add rewrite conf here change url to /dashboard/db/testdash?id=add
//Add the request header
>>>RequestHeader set X-T1 "value of the query parameter"
//Proxy
ProxyRequests Off
ProxyPass "/" http://localhost:3000/
ProxyPassReverse "/" http://localhost:3000/
Header always set Access-Control-Allow-Origin "*"
Header always set Access-Control-Allow-Methods "POST, GET, OPTIONS, DELETE, PUT"
Header always set Access-Control-Max-Age "1000"
Header always set Access-Control-Allow-Headers "*"
# Added a rewrite to respond with a 200 SUCCESS on every OPTIONS request.
RewriteEngine On
RewriteCond %{REQUEST_METHOD} OPTIONS
RewriteRule ^(.*)$ $1 [R=200,L]
I am completely new to httpd so don't how to do this!

Answer 1

remove ProxyPass since we want to use the variable
add RewriteRule (^/.*) http://localhost:3000/$1?%1
Note, this matching is not sufficient if the URL can ever have more keys at the end! A more robust regex would only gobble up the t1 value by capturing up to &. e.g. ^(.*)t1=([^&].*)(.*) then substitute %1%3
Add a quirky empty section to make up for the removed ProxyPass
<Proxy http://localhost:3000/ >
</Proxy>