str2threekeys
Select three keys from the line for sorting in tables (for 115.2 or 14a.1, etc.)
Call:
int str2threekeys(string sSource, double& k1,double &k2, double &k3);
Here:
sSource - source string.
The function returns the number of keys (numeric fields).
It reveals three numeric fields. Letters leads to numbers 10000+letter code,
k1,k2, and k3 return the numeric values of those three fields, or zero if the field is not found.