import re
y = r"This is (line 1 minus line 2)183,662,7203.004.00 Less test"
print(re.findall(r"\(line 1 minus line 2\)(\d{1,3}(?:,\d{3})*)\d*(?:\.\d+)* Less\b" ,y))
aW1wb3J0IHJlCgp5ID0gciJUaGlzIGlzIChsaW5lIDEgbWludXMgbGluZSAyKTE4Myw2NjIsNzIwMy4wMDQuMDAgTGVzcyB0ZXN0IgpwcmludChyZS5maW5kYWxsKHIiXChsaW5lIDEgbWludXMgbGluZSAyXCkoXGR7MSwzfSg/OixcZHszfSkqKVxkKig/OlwuXGQrKSogTGVzc1xiIiAseSkp