You have multiple questions. However I'll answer part of it by saying COUNTIF is an underrated tool for CHECKING if something exists or not. Countif is desirable because it can check cells without throwing errors as VLookup or Match might.
Example for checking if value exists in a range could be written like this in excel =OR(COUNTIF(E:E,"VNVININT2HAI"))
which would return True
if any cell had a value of your text.
You can also use it to check if a cell contains it by using * for the sides.
Example: =OR(COUNTIF(E6,"*2*"))
would return True
or False
depending if a cell contains a "2" anywhere in it.
I doubt this fully answers your question, but for people looking on how to "check cells and ranges" COUNTIF is probably more useful than you think. It's applicable in VBA too (sometimes I prefer it over instr).
EDIT
This works, but if you have a LOT of cells to check, perhaps consider using IsNumber(Match()
as shown in comments by @scottCraner
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…