It's possible to retrieve all your U.S. Trademarks by attorney name by using the TESS system. 

Here's the steps.

1) Go to http://tmsearch.uspto.gov
2) Next click the "Word and/or Design Mark Search (Free Form)" link.
3) Enter search string of ("attorney name")[AT] such as ("john smith")[AT] and click "Search Query" 
4) This will return a list of all trademarks where the attorney of record matches the name string.
Please note: there is not a way to be sure that this list is completely accurate. For example, numerous attorneys may be named John Smith. Thus, the search result may include more mark than expected. Further, the attorney of record for a given trademark may be spelled different from the others, including misspellings. Lastly, the attorney of record for a given mark may take some time to update in TSDR, if changes were recently made.
5) Press Ctrl-A or Cmd-A to select all text on the screen and then press Ctrl-C or Cmd-C to copy the text to your clipboard.
6) Open a standard text editor on your computer. Notepad for Windows and TextEdit for Mac.
7) Press Ctrl-V or Cmd-V to paste all the text. This will include some superfluous text on the top and bottom of the screen as shown in the first screenshot below. Remove all rows until the text starts with Row 1. Do the same for the bottom of the text.
8) Now you will copy and paste the text from your text editor into Excel. It should look like the 2nd screenshot. The 2nd column is the serial numbers.
9) If you have more than 100 marks, you will need to repeats step 5-8 for each group of 100 marks. There's a "Next List" blue button on the bottom of the first 100 rows of the TEES results list.

You can now use these serial numbers in a csv file to import into AppColl.

Warning: Please double check each row to make sure these are all your marks.