You might wanna try uPlayBink("01", 0); ... this should trigger the intro sequence of the game. The first parameter is the identifier for the video itself while the second parameter is the name of a RULE to execute after or while the video runs (don't know for sure).
You can see examples of this in the following files of the original campaign, if you've extracted the files via DATool:
universestoryrulesepisode_1.rules
universestoryrulesepisode_2.rules
universestoryrulesepisode_3.rules
universestoryrulesepisode_4.rules
universestoryrulesepisode_5.rules
universestoryrulesepisode_6.rules
universemissionsEPISODES 42___TheLocust.mission
/edit:
I don't know, where the movie files are given their identifiers, though.
/edit2:
Turns out these identifiers are given automatically. The Bink movie files are named nexus_XXX.dat and are being stored in the Nexus base folder. XXX will be used as identifier for that movie, so you may name your file nexus_stargateScene1.dat and use uPlayBink("stargateScene1", 0) in your mission to start that cutscene.