Help with Soccer Team Line-up generator/calculator

Hi guys and gals,
New to the forum and a very basic user of Excel with a new found learning desire for the program, but i think i've bitten off way more than i can chew with my latest 'project'.

I need help with designing a Football team line up calculator, for an online manager sim that i play, (Xpert Eleven)

The spreadsheet needs to do do one of two primary tasks:
1) Using a user selected formation (drop down list) generate a team as close to an average age of 26 as possible. OR..
2) Using a user selected formation (drop down list) generate a team as close to a user defined skill level as possible.

Within the spreadsheet, is the full squad listed with each players age and skill. I will manually enter these as my team changes so i dont need to pull the data from the website.

The sheet does not need to pull data/be connected with the actual website in any shape or form. I'm just trying to free up more time by concentrating on the tactical side of the game, rather than tinkering with different formations just to achieve the above results. Sometimes, for my own reasons, once i've decided on tactics, the players to be used are not important, hence the reason for automating this task.

I dont mind a patient teacher guiding me through this, but i'd like it fairly quick so if anyone would like to relieve some boredom, then be my guest.
PS layout and design is not important.

I have attached an example spreadsheet, but with the line-up manually entered to demonstrate the end result. The two checkboxes are to select either a line based on Age or skill.
Thanks in advance for any help