excel - How to use VLOOKUP result as COUNTIF criteria -

i want able determine how many times person's particular id (e.g. #123) has appeared in separate column (e.g. column c) given name (e.g. bob).

i have:

1. let column consist of several names. (bob)
2. let column b consist of ids relating person's name. (#123)
3. let column c consist of same ids, may contain duplicates of ids (might have 3 #123s)

the ids side-by-side each person's respective name.

how can use result of vlookup criteria (second argument) of countif function?

if use vlookup separately returns correct value i'm trying count. =vlookup(bob, column a:column b, 2, false) return #123

if use countif separately returns correct count value well. =countif(column c, #123) return 3

i've tried =countif(column c, vlookup(bob, column a:column b, 2, false)) returns 0.

i've tried referring criteria countif separate cell vlookup formula still returns 0.

so seems stops working when combine 2 together. might problem be, , might alternative?

@steve martin has valid point, assuming bob text, formula correct though syntax should be:

=countif(c:c,vlookup("bob",a:b,2,0))   

if using , returning 0 rather correct result reason #123 in columnb not same #123 in columnc. (in turn, reason 1 or more trailing spaces - not show on inspection of cells in columnsb:c).

to check, copy 1 of #123s columnc on top of first #123 in columnb right of bob. should see result greater 0 "on right track" , may want apply trim remove surplus spaces.

in short, vlookup attempts match actual cell content rather visible cell content , recognises difference between #123 , #123  though not display 2 differently.