implement variable increment in VB Code

someone guide me to complete the below task which is given in the attachment

can we declare the source data to copy as variable by code?

1. number of rows will be keep on increasing and so need to declare as non blank values as the last cell by only defining the start point.(B3: ~) whereas now we have defined as (B3:D7). The columns will remain same but the rows to be defined as variables.

2. i need to copy and paste special multiple columns adjacent to it. For example in the file shared by me previously, i need to copy the D3:D7 and paste special in Column H3:H7 and proceeding from that need to copy the B3:B7 column and to be pasted in I3:I7 column.

please guide me in completing the above task.

Hello Everyone,

please let me know the possibility on this process