Usage:
Takes a string and returns the requested substring.

Params:
	STRING 	= "text"
	FROM	= 1
	TO	= 3
	VARNAME = "variableName"

Syntax:
	<CF_GETSUBSTRING STRING="sailing" FROM="1" TO="4" VARNAME="newString">

	<CFOUTPUT>#newString#</CFOUTPUT>

Outputs:
	sail