You basically want an overlap PCR. Here is a protocol:

https://openwetware.org/wiki/PCR_Overlap_Extension

I think this could be possible  This is essentially what is done with SOEing (splicing by overlap extension) just like Hanna said.  You put two PCR products, which have a region of complementarity, into one reaction and that allows for annealing and extension of a spliced product.  In a "normal" PCR where this occurs by accident, it should be much more rare than the amplicon you want, but it could conceivably be cloned.

that depending of the template which uses