It'll work, I just have no idea how to escape special characters here, see my parent.
https://en.wikipedia.org/wiki/Unstructured_Supplementary_Ser...
In addition to the already mentioned code of [STAR]3001#12345# there is also [STAR]#06# which will show your IMEI.
There were plenty of others (including spelling out 'WARRANTY' to get the manufacture date of the phone) but I forgot most of them.
Interestingly, on the iPhone, dialling anything of the format [STAR]# ...anything... # will cause the screen to go grey as if a separate app, then after a short delay tell you that your code was invalid.
For anyone who is confused:
Star #3001#12345# Start
I love how it opens up a separate app. Good stuff
*3001#12345#* I'm an asterix * and I'm ok
[ed: ***proof-no-space*required**]
However, a single asterix * with spaces on both sides is also "escaped": I * blink * all day and sleep all night?So: " * #999# * " should work.