Need help... I'm pulling my hair out on this.

In VBA,

I have a user form with different textbox.

I need, when there is something entered in the box (lets say the first
one - textbox1), excel to browse through a apecific non-contiguous
range
( Range("A1:C1,E1:G1,A4:C4,E4:G4,A7:C7,E7:G7,A10:C10 ,E10:G10") )

And find the first empty cell. Change the value of this cell and the
next 9 (10 total) by the value of a variable ("NoLot1")
I tried many different things, nothing worked.

HELP PLEEEEEAAAASSSSE!