Uppdatering med lite mer info (dock på Engelska :))

Hi.
I hope someone will be able to help me.

This is what I got.
2 customers, each customer have 5 material (2 of the is the same).
These 8 different materials have different weight and the 2 same materials have same weight.

Sheet1
Cell A1 Customer 1
Cell A2 Material 1
Cell A3 Material 2
Cell A4 Material 3
Cell A5 Material 4
Cell A6 Material 5


Cell B1 Customer 2
Cell B2 Material 6
Cell B2 Material 7
Cell B2 Material 8
Cell B2 Material 4
Cell B2 Material 1


Sheet2
A1, Material 1, B1 17,856, C1 1,984, D1 9
A2, Material 2, B2 17,226, C1 1,914, D2 9
A3, Material 3, B3 17,532, C1 1,948, D3 9
A4, Material 4, B4 18,552, C4 2,058, D4 9
A5, Material 5, B5 18,198, C5 2,022, D5 9
A6, Material 6, B6 22,644, C6 2,516, D6 9
A7, Material 7, B7 19,071, C7 2,119, D7 9
A8, Material 8, B8 19,683, C8 2,187, D8 9

Cell A1-A8 Material
Cell B1-B8 Total weight
Cell C1-C8 Weight for 1 pc
Cell D1-D8 9 pcs

This is solved. ComboBox 1 Customer, ComboBox2 Material.

This is what I need help with.
Based och the Customer and material from ComboBox, I need a TextBox where I can type in a surten weight eg. 200, then I need a calculation and a result in TextBox 2. That will calculate TextBox1 divided with the total weight from material (value in TextBox1 (200) divided with Material 1 (from ComboBox2, total weight is 17,756) 200/17,856 = 11 (need to have adjusted to the nearest number without decimal)).

Is this best to use a UserForm or direct in the Excel sheet. I would like to have a Userform that will open when the Excelfile is opened and have a close button that will close both Userfom and Excel sheet.

I hope this is possible.

Thanks for your help 
Regards
//Patrik