FoxPro DOS program code when run under VFP, will look "funny" due to the Windows default fonts. While you can run .PRG, .SPR and .MPR files in VFP, .SCX's, .MNX's, .FRX's, and .LBX's will need to be converted before they can be "compiled". The success of this conversion will depend a great deal on what features were used and how old it is (2.6 has a much better chance than 2.0 files). Also if the DOS apps used any .BIN, or .PLB files these will need equivalent functions and if they used low-level IO to access hardware features, these probably won't work.
Plan on spending a lot of time to get it right - one reason most everyone suggests a re-write, especiially if you've got the time and "money".
Rick