This is definitely a job for Real Band, Ricky. Can you play some keys and do you have a keyboard controller? If so, in RB set up your drum VSTi and just play the part in midi using your controller. Since it's midi, no problem to set up your tempo to slow down using RB's tempo map. The only problem there is if you already have audio tracks in the project. They won't change tempo, that's why I said earlier this needs to be an all midi project at least until you get that transition done.
As far as inserting an existing drum part into an existing project, that's just cut and paste. What I have done in the past is to use parts from different midi files like drum tracks. I've got a whole library of midi files where the song itself may sound like crap but it has a hot drum or percussion part. Some of them are files where some hot drummer played the drum part live on a midi kit so it sounds very real. I'll copy that part into another project in RB and just cut and paste it in. Since it's midi, the tempo will match automatically and you can easily edit the timing if it's not exactly right. I use Jamstix for the drum sounds and their kits match perfectly with most of the Real Drum tracks. As you've found out, the RD's can't create song specific fills or transistions so you need a new midi part for that. You can also create as many midi drum parts as you have patience for using Biab styles. A Biab drum part using a Jamstix kit can sound pretty good. Put a part marker on every bar for 24 bars or something, click on any empty track, pick a style and let RB generate it in just a second or two, then do another 24 bars using a different style and keep doing that until you hear something that works. That's the beauty of RB, you could fill up 20 tracks with 20 styles like that.

Bob

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