I need a User Defined Function that check if a number or string is 8 digits
long and ends in "0000". If it meets the two creteria, then it should drop
those the "0000" and return only the remaining 4 numbers for example,

23000016 result 23000016
23160000 result 2316
19000000 result 1900

FYI using Substitute() gives me the wrong result sometimes.

FUNCTION Truc(location)

END Function