SDK Question Find configuration from multistage vessel

[Bj]

Specifically I am looking for a (better) way to get the configuration number on the space shuttles, like;

STS-101:Atlantis
...
CONFIGURATION 3
...
END

The way I have it is I think poor, every second or so it will save and then read the saved file. Works OK, but I suspect it is not the only way. Anyone else have any other methods?