I don't understand the following line of code.
"=MID(R[0]C[-2],INDEX(FIND({""(403"",""(587""},R[0]C[-2]),MATCH(TRUE,ISNUMBER(FIND({""(403"",""(587""},R[0]C[-2])),0)),14)"

1. Why and when should square brackets be used?
2. Why & where should curved brackets be used?
3. Why are there double sets of quotation marks around the (403 and (587
4. I've never used the R[0]C[-2] nomenclature. Is this example designating a
cell location that is on the same row bur two columns left?
5. I can't find reference to MATCH(TRUE,ISNUMBER. What is this doing?

Thanks to anyone that takes the time to answer this.

Jim Berglund