Merge Spreadsheets

Hi all,

Wonder if anyone can help.. I'm trying to merge over 60 excel files into one however the files are password protected and there are 6 tabs in each spreadsheet.
Any ideas on how to quickly merge the files?

Example
one.xlsx tab = a,b,c,d,e
two.xlsx tab = a,b,c,d,e
three.xlsx tab = a,b,c,d,e
four.xlsx tab = a,b,c,d,e

Output:
Master.xlsx with 5 different tabs.
So All the sheets labelled a merged together,
then all the sheets b *5 merged together etc etc
to create one master file with 5 tabs and all the relevant data.

I have tried a Macro but it keeps failing due to errors.

Thanks for looking. Have a good weekend.