Deleting rows based on a certain columns 'prefixes'?

For one of my columns within an excel spreadsheet, I have department numbers that consist of five digits.
I am hitting a roadblock in writing a macro that will delete any row containing department numbers that begin with a certain combination of 2 numbers.

Example:

Dept: \ Hours:
10301 \ 134.11
10303 \ 45.10
10310 \ 169.05
10311 \ 37.69
11332 \ 4.50
11363 \ 433.12

Would need to delete rows containing those starting with an 11 underneath the department column, without effecting other departments or the hours column



In addition, is there any type of macro that, after deleting those numbers starting with 11, would also delete all of the other 'prefixes' (so delete the first two numbers on all of the departments?)

Thank you so much.


(Sorry, I cannot provide a sample workbook, due to using this for sensitive timesheet information within my company)