Ok, so I've put tested your code with Kixtarter, but it doesn't seem to be working.
Code:
$oldName = "abcnt04"
$newName = "abcnt32"
for each $section in readprofilestring("C:\blah1.ini","","")
for each $value in readprofilestring("C:\blah1.ini",$section,"")
$splittedValue=split(readprofilestring("C:\oasis1.ini",$section,$value),$oldName)
if 0<ubound($splittedValue)
$nul = writeprofilestring("C:\blah1.ini",$section,join($splittedValue,$newName))
endif
