Under biblatex, you can override the bibliography drivers as done below. However I probably wouldn't handle the problem this way. The bibliography drivers save you from having to worry about too much format, line breaking, spacing and punctuation. They also ensure entries of the same type are set consistently and can handle bibliographic data in a flexible manner. Considering this, I'd probably reformulate this question or ask a new question providing an example with the problematic entries and the output you're wanting to achieve.
\documentclass{article}
\usepackage{filecontents}
\usepackage[american]{babel}
\usepackage{csquotes}
\usepackage[style=apa,backend=biber]{biblatex}
\DeclareLanguageMapping{american}{american-apa}
% Identify bib entries that must be manually set
\makeatletter
\AtEveryBibitem{%
\ifthenelse{\iffieldequalstr{entrykey}{7.01:1}%
\OR\iffieldequalstr{entrykey}{7.01:2}}
{\def\abx@field@entrytype{customa}}
{}}
\makeatother
% Provide text for manual entries
\DeclareBibliographyDriver{customa}{%
\iffieldequalstr{entrykey}{7.01:1}
{Entry 7.01:1 --- Herbst-Damm and Kulik. \mkbibemph{Volunteer Support...}}
{}%
\iffieldequalstr{entrykey}{7.01:2}
{Entry 7.01:2 --- Gilbert et al. \mkbibemph{Effects of...}}
{}}
\begin{filecontents}{\jobname.bib}
@ARTICLE{7.01:1,
AUTHOR = {K. L. Herbst-Damm and J. A. Kulik},
TITLE = {Volunteer Support, Marital Status, and the Survival Times of Terminally Ill Patients},
JOURNALTITLE = {Health Psychology},
VOLUME = {24},
PAGES = {225--229},
YEAR = {2005},
DOI = {10.1037/0278-6133.24.2.225},
URL = {http://some.url}
}
@ARTICLE{7.01:2,
AUTHOR = {D. G. Gilbert and J. F. McClernon and N. E. Rabinovich and C. Sugai and L. C. Plath and G. Asgaard and D. Dickinson and N. Botros},
TITLE = {Effects of Quitting Smoking and {EEG} Activation and Attention Last for More Than 31 Days and are More Severe With Stress, Depedence, {DRD2 A1} Allele, and Depressive Traits},
JOURNALTITLE = {Nicotine and Tobacco Research},
VOLUME = {6},
PAGES = {249--267},
YEAR = {2004},
DOI = {10.1080/14622200410001676305}
}
@ARTICLE{7.01:3a,
AUTHOR = {T. J. Sillick and N. S. Schutte},
TITLE = {Emotional Intelligence and Self-esteem Mediate Between Perceived Early Parental Love and Adult Happiness.},
JOURNALTITLE = {E-Journal of Applied Psychology},
VOLUME = {2},
NUMBER = {2},
PAGES = {38--48},
YEAR = {2006},
URL = {http://ojs.lib.swin.edu.au/index.php/ejap}
}
\end{filecontents}
\addbibresource{\jobname.bib}
\begin{document}
\nocite{*}
\printbibliography
\end{document}

.bblfile that is generated by BibTeX? It's not a good way, as that file is regenerated on each BibTeX run, hence you would have to do the change only after the final run of BibTeX. – Torbjørn T. Aug 11 '11 at 13:01natbibandbiblatex-apa. Are you open to abiblatex-only solution? Bibliography drivers can be overridden... – Audrey Aug 16 '11 at 18:49biblatex-apa. – Speldosa Aug 16 '11 at 22:05biblatexit seems to me that you shouldn't need to do this. Do you have a specific example of a particular entry type that you are having difficulty with? (i.e. a bit more detail on your painting example and what Mendelay gives you in the.bibfile.) – Alan Munn Aug 16 '11 at 23:43