May be you are looking for the Automatic Sweeper Transition feature.
Here are a few general things about it:
The default 'Attenuation Settings' can be defined in the general settings, section "Mixing/Fading" - see the related button.
(e.g. the 'Convert To Sweeper' function from the playlist context menu uses these settings)
The default "Transition Type" can also be defined in the general settings, section "Mixing/Fading".
Note, that you can define for a certain Media Entry Type an automatic track insert transition (see general settings, section "Mixing/Fading" and click on the "Mixing per Media Type..." button - now select the related Media Type and take a look to the 'Automatic Track-Insert Transition' setting). All tracks of that media type would than automatically be converted into a Sweeper (blending with either the end of the previous track resp. start of the next track).
To place a Sweeper over an existing playlist entry can also be done via drag and drop of e.g. a Jingle or Station ID track and then holding down the ALT-key. When you now drop such a track you are even asked about the Attenuation and the Transition Type.
What you are maybe looking for is the script-related automatic Sweeper Transition.
Within your script-editor add a script-line and choose your script-mode and entry to pick a StationID track you want to pick (ie. as shown in the picture below). Now click on the flash icon in the 'Options' column and select a transition mode:
There are various different sweeper transition types you might use. E.g. the "VO_StartWithCueInOrEndWithRampOfNextTrack" tries to align the sweeper track to the end of the ramp of the next track. In case the ramp time is longer than the sweeper track itself, it will be aligned to the cuein position. If no ramp position is given, the sweeper track stays into the playlist by its own and will be started normally with the next cue point of the previous track, which is also case, if the sweeper track is longer than a given ramp time.
You might try out the different transition type manually first (via rag and drop plus the ALT-key; as explained above) in a new and empty playlist to see what matches you most.