Sub bidule()
Dim chaine$, char$
chaine = "totox mange des pommes"
char = "x"
test1 = InStr(1, chaine, char, vbTextCompare) > 0
test2 = chaine Like "*" & char & "*"
test3 = Not Len(Replace(chaine, char, "")) = Len(chaine)
MsgBox test1 & vbCrLf & test2 & vbCrLf & test3
End Sub