Uh....No, it is NOT ok. According to the National Electrical Code, cabling installed in buildings must be rated for the enviornment it is in (CM, CMR, CMP, etc for communications cables.
PE type cables for outdoor use are NOT rated, and as such are illegal to run iside the structure. The electrical code allows you to use this building entrance cable to feed service into the building provided you do not run it more than 50' inside the building and ground the sheath as close as practical to the entrance point. You may run the cable farther than 50' (at least for entrance cable) IF you encase it in rigid metal conduit all the way to the backboard where it is terminated, grounded and protected.
Good Luck!
It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com