替换？ 到和.htaccess

I have url http://example.com/index.php?roure=test/test Payment system calls http://example.com/index.php?roure=test/test?var=val I need make it http://example.com/index.php?roure=test/test&var=val in htaccess How can I do it?

Try :

RewriteEngine On

RewriteCond %{THE_REQUEST} /index.php\?roure=test/test\?var=val [NC]
RewriteRule ^ /index.php\?roure=test/test&var=val [NC,L,R]