mid - luxembourg/muxcode-clm GitHub Wiki
MID()
FUNCTION: mid(<string>, <first>, <length>)
If <length> is positive, mid() returns a segment of the string starting with <first> and continuing to the right until the end of the string or <length> character whichever is satisfied first.
If <length> is negative, mid() returns a segment of the string defined in a reverse fashion. That is, mid() returns a segment of the string ending with <first> and continuing to the left until the beginning of the string or until <length> characters whichever is satisfied first.
Note that the first character in a string is numbered zero, and not one.
Left() is supported as an alias for strtrunc().