Merge Excel Documents

I have 3 spreadsheets which need linking. The objective is to populate a final spreadsheet which contains company name data and bringing through the person of significant control, or persons.

- 6 spreadsheets that are 412 mb in size which contains Company Name and Company number - http://download.companieshouse.gov.uk/en_output.html
- Another 21 notepads which can be opened in excel which are 1.17GB which then contains company number and person of significant control. You can split the data using text to columns but the person(s) are often not in the same column and they need to be - http://download.companieshouse.gov.uk/en_pscdata.html
- The last spreadsheet contains information on who is the registered person of a daycare nursery but often it is the company name. I need to pull through the persons of significant control by linking the company name to the previous sheets.

The final spreadsheet is 10mb and I can send via we transfer.