Use InStr function

InStr([start_pos],str_to_search,search_for [,compare_type])

Ex:

Dim x as Integer
Dim strToSrch as String

strToSrch = "This is so easy..."
x = InStr(strToSrch, "easy")

If string was found the value of the x will be stating position of the string (in this case x=12).
If string was not found then x=0