Your 'special categories' sound like the 'Highly Skilled Migrant' category. Now it's not clear what would qualify for that -- it sounds like it's something you can argue for any skill if you can provide evidence. However that doesn't exempt you from the work visa, it just makes the process simpler. From the Russian Embassy in the UK website:
A foreign citizen can apply to a Russian Consulate with the intention to work as a highly skilled specialist.
The application form is filled in the Russian language either legibly handwritten or printed. The information about the applicant will then be placed on the website of the Federal Migration Service of the Russian Federation (www.fms.gov.ru/useful/patent/index_eng.php).
The following information should be provided in the application:
passport data in Russian and in Latin letters (as in passport);
information confirming the experience of the foreign citizen, his/her
skills or achievements in a specific field;
contain information on recommendations if any, confirming expert
knowledge and qualification;
consent to include the information
provided by the applicant in the data base within the state system of
recording migration as well as consent to forward these personal
details to employers and sponsors on the territory of the Russian
Federation that has to be confirmed by signature.
So first you have to have all of that (and be able to fill in the application from in Russian!). But this only means you skip some paper work, once you've been accepted as highly skilled (from the same page):
- A business visa for the foreign citizen is then granted on the basis of an invitation to enter the Russian Federation to hold relevant talks, provided for the foreign citizen by an employer or a sponsor.
There's more on that page, you also need a bank balance of at least 6000 Euro and this page says you need to be receiving a salary of more than 2 million rubles and be planning to stay for 3 years.
So, you definitely should apply from abroad. Getting yourself in the highly skilled category will definitely help and seem almost essential if you want to live there (other work permits seem limited to 90 days). BUT you are definitely going to have to get your future Russian employer to do this for you. Every time I've got a visa for Russia I've had to rely on people in Russia to provide the required paperwork, doing it yourself is just a recipe for getting rejected.
Also, I'll just note this, if you don't fall into the highly skilled category you only have a few days to get your future employer to start the ball rolling (from my second link):
Almost a full year before actually hiring an expat, companies operating in Russia have to apply for corporate work permits for their future foreign employees.
The deadline for the foreign labor needs forecast is May 1st. Companies are informed how many and which of their applications have been accepted in the following months, usually in summer.
Perhaps someone who has done this themselves can come along and give more advice but I would recommend you get some professionals involved to help you.