need help: Cell check

I just cant find how i can test of my cell got follwing format:

AAA-000

A= A character
0= A number

if the format is like jonas-154 he must give a false back in a if statement because it must be jon-154
or when it is 145-478 it must give error beceaus it must be chacters and then -
and also i want something that test if there is more than one - in a cell

pleas react fast need it fast

thx jonas "Spykie" verhaert

If you put the following in as a data validation (custom):-

=IF(AND(CODE(LEFT(A1,1))<123,CODE(LEFT(A1,1))>96,CODE(MID(A1,2,1))<123,CODE(MID(A1,2,1))>96,CODE(MID(A1,3,1))<123,CODE(MID(A1,3,1))>96,CODE(MID(A1,4,1))=45,LEN(A1)=7,ISERROR(VALUE(RIGHT(A1,3)))=FALSE),TRUE,FALSE)

This will check that the first three characters are a-z (lowercase only), the fourth character is a hyphen and the fifth to seventh characters are numbers.

It won't allow any more than 7 characters and will error if the letters are put in in uppercase.

Thx i needed it hard