occurrence in Listview

In a second column of Listview i can have:

1334
1335
1238
1238
...

And a myvar="1335" i need to count how many values in the column of listview are <> myvar..
In this case are only 2 (the 1334 and 1238), how To?

Note:
In this case the values in column are only 4 But i Can have approx 50/90 value in column