Originally Posted by ShneekeyTheLost
Not in Core, there isn't... read the OP again.
Ah my apologies, I missed your post. My comments about dip-entry to Loremaster still stand; it's maybe not the most optimized build ever, but certainly entirely playable and will get him in without much muss and fuss.
As to Core-only PrCs... well, he didn't actually say "Core", he said "SRD". And in SRD there's Battle Sorcerer 6
/ Fighter 1 / Eldritch Knight X
, which is again maybe not the most optimized, but very easy to play, will give him good hands-on experience with arcane magic, and should be at least reasonable even if he messes up spell selection. Battle Sorc will improve his gish-ness and let him actually wear armor (a weakness in Eldritch Knight as-printed), and he'll still hit 9th level spells eventually.