If there is anybody still looking at finding an alternative for using commas in a csv lookup file, because they CAN'T use commas, because their fields contain commas, GOOD NEWS:
You can use quotes as text delimiters and commas as field delimiters in the following fashion:
"field1","field2" "example1 , that contains commas","something" "example2","" "","example3"
Splunk correctly extracts field value pairs!
I don't think so. You can't upload those via the GUI, and the ones you place in the lookups folder won't work right with semicolons.
Someone feel free to correct me if I'm mistaken!