Basic maths would suggest that there are 22 positions (as you think not the first or last word)... and 2025 word possibilities (most wallets don't re-use seed words).

A python script should be able to rip through the 44,550 combinations fairly quickly... even allowing for having to generate the masterkey, and move down the correct derivation path to check the first address is the same as what you have.

Which wallet were you using? and do you have a record of at least 1 address that the seed generated?

Also, depending on the wallet, it may be possible to extract the seed directly (If it is bitcoinj based... ie. MultiBit) from the wallet file. Which leads to my next questions... if you have the wallet, what is stopping you from simply exporting the seed from the wallet application? Did you lose your wallet encryption password?