Create a helper form to fill in Column with several conditions

Dear All,

I need help to create a form (by click button in "RGST" Sheet) to fill in column with several conditions (file attached).

The following conditions are:

1. ComboBox Date contains unique data from Date column (Sheet PAY).
2. ComboBox #RCP contains unique data from the RCP column (Sheet PAY) that corresponds to the Date and not yet listed in the # RCP column (RGST Sheet).
- For Example: If 22 September 2017 selected, it will show the receipt number: 6856,6857,6858,6859,6860,6861,6862,6863,6864,6865,6866,6867,6868,6869,6870,6871,6872,6873,6874 on the ComboBox list.
3. The Amounts indicate the Total Value of the selected Receipt Number (Payment Sheet).
4. TextBox is a multicolumn textbox containing unique data from the Unit Name (Sheet RGST) where for the first column is the Unit Name, the second column is Description (filled in "CL" or blank), the third column is the Amount of the "Total" column (Sheet RGST).
5. As for the data with the description "CL" is the name of the unit that has data in the "Receivables" column which is negative.
6. The unit name data in the TextBox follows the following conditions:
- Unique data from the Unit Name that matches the date and data in the # RCP column is still empty.
- Unique data from Unit Names that have data in the "Receivables" column is 0 or negative.
- For Unit Names that have negative data in the "Receivables" column, the information is "CL".
7. More detailed explanation is found on Sheet3.

I hope my descriptions are clear enough and you understand for what i mean.

Thank you

Omega Boost