<p>I have a .bat and inside the .bat i would like to execute a special code if there's some modification inside the svn repository (for example, compile).</p>

Are you wanting this to be reactive? Or, on-demand?
For reactive, see
hooks
. The script will have to be named according to it's purpose:
pre-commit.bat
,
post-commit.bat
. The scripts are called as:
[script] [repos-path] [revision-number]
For, on-demand:
Working Copy
svn log
svn st
svn diff
svn proplist
Repository
svnlook author
svnlook changed
svnlook date
svnlook diff
svnlook history
Example:
```
```
svn st "C:\path\to\working\directory\" >> C:\path\to\working\project.log
```
```
Every time you run the BAT, it'll add the
st
output to
project.log
. Adjust as needed.