There are a number of possible options. I have done a lot of work with AutoCAD files.
Do you have a range of numbers or are the all single digit numbers?
if they are single digit simply do a search by attribute for TextString = '1' or TextString = '2' etc.
Or take your file and export the table to a text file. Select the TextString column and press the Sort A to Z button.
Excel will sort your data by Integers first, then entries that start with a decimal then by those that are a string but start with a number and then by those that start with a Character. To be more technical about it Excel will sort by pure numbers first and then by lowest ASCII code value. i.e. ALT 034 is " or ALT 033 is ! so it would sort the ! first.
All that aside. Now you can delete all the other columns in your Excel table other than the one with the numbers.
Below is an example of what I did in Excel. Pure numbers are sorted first then lowest ASCII character.
Now simply Delete all the rows in the table that are larger than a number. Save your table. Bring it back into ArcGIS and join the NumberColumn to the TextString keeping only matching numbers. Export the joined Table as a new feature class.
IF your lower case characters are only single characters. IF your feature with the TextString is a ShapeFile you can add a through z to the bottom of your number column in Excel and it should result in a case sensitive result.
NumberColumn |
0.1002 |
1004 |
1005 |
9999999 |
!<1009_16 |
"100 |
.1002_17 |
1001 15 |