Find all birthdays from all worksheets

[Ipharis]

Hello. This is my first post in here so excuse me for my complicated explanation.
I have a workbook where I have about hundred worksheets.
First worksheet is so called frontpage and the others are clients/companies.
Worksheets are named accordig to the clients and companies.
In cli/com worksheets I have contacts in D12:D41 and their e-mails, phonenumbers, positions in company and
most importantly their birthdays at column I.
From here we get to the problem. When I have almost hundred companies and each one of them has from 10
to 30 contacts. Roughly 1500 contacts and their birthdays (DD.MM.YYYY). I can't simply remember them all.
So...
Within frontpage in B11:B110 I have the companies listed in input order and in G11:K110 I have range/area
for the birthdays.
I need macro to retrieve all birthdays from all worksheets that are within three weeks.
For example I click the 'Update Birthdays' -button and macro gets three birthdays from
worksheet 'Company F' and alinges the birthdays in frontpage to the birthday area (G11:K110)
from left to right to corresponding row. Company F is located in B16 so the birthdays should be seen at
G16, H16 and I16 in order from closest date to furthest and from left to right.
Any ideas?