Dynamic Drop down lists via macros

Hi,

I'm trying to sort some kind of dynamic data validation list. I have attached a sample spreadsheet to assist. Under the project tab i have a heading called client name, next to it is a drop down list of company names pulled from the customer database tab. Once a company has been selected i would like the contact name dropdown box to only have the names relevant from that company (see customer database for full information) I will then use VLOOKUP to auto populate the correct information.
Finally in the delivery address i would like this to pull the two addresses on file (see customer database) in a drop down list to select one.

I've been advised i cannot do Dynamic data validation as i would have to re-arrange my data. (customer database has over 1000 lines of info) However macros can help. I have never used macros so be gentle, can you help?

Hi thanks for your prompt reply.

I have uploaded the file with more detail, unfortunately i cannot give you our exact file for data protection. The spreadsheet is a like for like representation of the full version but just not with real content.

In order to do the dynamic data validation i was advised that i would have to change the layout of my customer database to make this work. However the full database has over a 1000 lines of customer contact information, re-working the layout would be a tedious job.

In a nutshell im trying to do the following:

The company name cell has a data validation drop down box. Once a company name has been selected the invoice address is added via VLOOKUP.
The contact name cell should be also be a drop down data validation and should only provide results based on the company name entered in above.
The example in the workbook is company EIC123. This should return 4 names in the contact name cell to enable the user to select one.
The Phone number and email will also be pulled in via VLOOKUP.

From the original advice from excelchat online was that it couldn't be done from the front end excel but from the back end using macro. I'm not familiar with macro language and wouldnt know where to start with this.
would you be able to assist me?