In general, you can specify smaller units within containers:
char 3 of word 1 of field 1
first word of field 1--Words are separated by spaces.
item 2 of the mouseLoc--Items are separated by commas. For example, the mouseLoc returns 23,60.
line 4 of field 1--lines are separated by Return characters, not by starting at the next left margin. For example, this entire definition of "line" is just one line.