I can't bookmark search results because it's a result of form submission.

Here's the actual scenario: I'm waiting a package sent by Royal Mail, tracking number RU098755913GB

1. Go to https://www.royalmail.com/track-your-item
2. Enter tracking number RU098755913GB
3. Bookmark search results
4. Try to restore results by clicking your newly created bookmark - clear form is shown, where I need to enter my tracking number again - no speed gain at all.

As far as I understand, that's because bookmark saves only page URL which does not contain my tracking number, because number was sent with form POST data

Here's how I do it:

1. Right click on tracking number entering field and select "create search engine"
2. Assign some shortcut for it, let's say "rm"
3. Create a new bookmark and manually modify it's address to "rm RU098755913GB"

If clicking the bookmark would work the same way as if I entered "rm RU098755913GB" into Opera url address field, then I would see my search results - exactly the thing I want.

However bookmark address is formatted as url upon saving and bookmark address becomes rm%20RU098755913GB which is an URL pointing nowhere. I have to manually modify it and replace %20 with a space to get to my results.

Is there a possiblity to make a bookmark which upon clicking would work the same way as if I typed "rm RU098755913GB" into the Opera address field? Like some kind of typing macros. It would really help me / speed up tracking.

Some sites (e.g. mail tracking) only accept POST data. That is, you can not bookmark something like http://packagetrack.zzz?id=XXXNNNN and receive results. However, Opera supports wonderful search engine shortcuts. I can click form and bind entry field to something like "pt XXXNNNN" which will post data and return my tracking info.
The thing I lack is ability to set bookmark address to something like "pt XXXNNNN", because Opera automatically encodes it as URL "pt%20xxxnnnn" which points nowhere. I have to set address as pt_XXXNNNN and after clicking bookmark, go to address bar and remove underscore symbol by hand. I can live with that but it is far less convenient than if the search shortcuts like "pt XXXNNNN" wouldn't be converted when stored to bookmark address.