Matching pattern in PERL

Hello,
 I need to verify a string from the command line in a PERL script.  I  need to make sure that the string has the following format:

ABS <A-Z><A-Z><A-Z> <0-9>.<0-9>.<0-9> <A-Z><number> <A-Z><number>

here is a sample:

ABS MSI 9.8.5 A209 B203
ABS HGF 9.8.5 A1234 B6456

i.e. of not valid strings:

SABS MSI 9.8.5 A209 B203
ABS HGF 19.8.5 A1234 B6456
ABS MSI 9.84.5 A209 B203
ABS HGF 9.85.5 A1234 B6456
ABS MSI 9.8.5 A209 B203D
ABS HGF 9.8.5 AB1234 B6456

(in words: ABS 3 letters, space, number.number.number letternumber letternumber)
String needs to start with ABS, then the rest of the sequence.

This is what I was trying but it is not working:
($LABEL =~ /^ABS [A-Z][A-Z][A-Z] [0-9]\.[0-9]\.[0-9] A[0-9][0-9][0-9] B[0-9][0-9][0-9]/))

Thanks