Unless you already had another folder in the Dynamix folder with the same first 6 characters first, the number would be 1. The number is assigned in order of creation. DOS names are limited to eight characters with a 3 character extension. Spaces are disallowed. Long file names remove these limitations, but still have a 8.3 version so as to be readable by DOS. When working within Windows since Win95, these DOS names are auto generated. It starts with the first 6 DOS legal (no spaces) characters, a tilde ("~") and a number, starting with "1" in order of creation.
If the Dynamix folder had a, say "3D Ultra Pinball 3" folder in it first and then a "3D Ultra Pinball 1" folder was later created, the Pinball 3 folder would get "C:\Dynamix\3DULTR~1" and the Pinball 1 would be assigned "C:\Dynamix\3DULTR~2". This would be followed by no more than a 3 character extension, so ".html" would become ".htm", i.e. MyPage.html becomes MYPAGE~1.HTM.
Run the diagnostic tool and attach the results here.
01000010 01111001 01110100 01100101 00100000 01101101 01100101 00100001